docs: adding GMP examples code (#2499)

* adding GMP examples code

* ++

* updated gmp docs

* updated gmp docs

* remove go structs and added links to msgs

x/uibc/gmp/README.md

@@ -0,0 +1,181 @@
+# GMP Handler
+
+Cross chain transfers using Axelar General Message Passing (GMP)
+More info about cosmos GMP find [here](https://docs.axelar.dev/dev/cosmos-gmp)
+
+## Axelar IBC Memo
+
+The memo structure is represented by the [Memo](https://github.com/umee-network/umee/blob/main/x/uibc/gmp/types.go)
+
+When a user wants to execute leverage supply, supply collateral or liquidate transaction using Axelar GMP , user have to set JSON serialized `Memo` into the GMP payload.
+In the example below, change the [payload](https://github.com/axelarnetwork/evm-cosmos-gmp-sample/blob/main/native-integration/multi-send/solidity/contracts/MultiSend.sol) field and version, for now we are supporting `uint32(2)` version.
+
+## Supported Leverage Msgs through Axelar GMP
+
+### Supported messages
+
+- [MsgSupply](https://github.com/umee-network/umee/blob/main/x/leverage/types/tx.pb.go#L36)
+- [MsgSupplyCollateral](https://github.com/umee-network/umee/blob/main/x/leverage/types/tx.pb.go#L508)
+- [MsgLiquidate](https://github.com/umee-network/umee/blob/main/x/leverage/types/tx.pb.go#L398)
+
+## Example transfer from fantom EVM to umee using Axelar GMP
+
+```bash
+# clone the repo
+$ git clone https://github.com/axelarnetwork/evm-cosmos-gmp-sample.git
+$ cd evm-cosmos-gmp-sample/native-integration/multi-send/solidity
+
+# Build the contracts on this repo
+$ npm run build
+
+> [email protected] build
+> rm -rf artifacts && hardhat compile
+
+Compiled 13 Solidity files successfully
+```
+
+## Deploy `MultiSend` contract on fantom evm testnet
+
+> Add below code into `deploy-umee.js`
+
+```js
+'use strict'
+
+const {
+    providers: { JsonRpcProvider },
+    Wallet,
+    ContractFactory,
+    constants: { AddressZero },
+} = require('ethers')
+
+
+const fantom = {
+    name: 'fantom',
+    url: 'https://rpc.testnet.fantom.network',
+    confirmation: 1,
+    privateKey: 'cf469f1c4b06a6204bb9f977fa2865271a17a4ed2028ba4c064fea4754e81c83',
+    gateway: '0x97837985Ec0494E7b9C71f5D3f9250188477ae14',
+    gasService: '0xbE406F0189A0B4cf3A05C286473D23791Dd44Cc6'
+}
+
+const MultiSend = require('./artifacts/contracts/MultiSend.sol/MultiSend.json');
+
+(async () => {
+    const wallet = new Wallet(
+        fantom.privateKey,
+        new JsonRpcProvider(fantom.url),
+    );
+
+    console.log("Address: " + wallet.address);
+    const factory = ContractFactory.fromSolidity(MultiSend, wallet);
+
+    const contract = await factory.deploy(fantom.gateway, fantom.gasService)
+    const tx = await contract.deployed();
+
+    console.log(`multi send contract deployed on ${tx.address}`);
+})();
+```
+
+Deploy the contract
+
+```bash
+$ node deploy-umee.js 
+Address: 0x68B93045fe7D8794a7cAF327e7f855CD6Cd03BB8
+multi send contract deployed on 0xf3bF4B57c5cf252BF940C80Df41d02834935FF3b
+```
+
+Deployed contract address : `0xf3bF4B57c5cf252BF940C80Df41d02834935FF3b`
+
+## Execute the transfer from fantom evm to umee using axelar gmp
+
+> Add below code into `interact-umee.js`
+
+```js
+'use strict'
+
+const {
+    providers: { JsonRpcProvider },
+    Contract,
+    Wallet,
+    ethers,
+} = require('ethers')
+
+
+const MultiSend = require('./artifacts/contracts/MultiSend.sol/MultiSend.json');
+const IERC20 = require('./artifacts/@axelar-network/axelar-gmp-sdk-solidity/contracts/interfaces/IERC20.sol/IERC20.json');
+
+const tokenAddr = '0x75Cc4fDf1ee3E781C1A3Ee9151D5c6Ce34Cf5C61';
+const contract = '0xf3bF4B57c5cf252BF940C80Df41d02834935FF3b';
+
+const fantom = {
+    name: 'fantom',
+    url: 'https://rpc.testnet.fantom.network',
+    confirmation: 1,
+    privateKey: 'cf469f1c4b06a6204bb9f977fa2865271a17a4ed2028ba4c064fea4754e81c83',
+    gateway: '0x97837985Ec0494E7b9C71f5D3f9250188477ae14',
+    gasService: '0xbE406F0189A0B4cf3A05C286473D23791Dd44Cc6'
+}
+
+// args
+const destChain = 'Umee';
+const destAddress = "umee1grechyg9el4fp36vk4typzrwyfqk4cpemmy6ya"
+const receiver = ["umee1ffzd88cg4qj0jndjaqnv3py2u3vp9tv0jnupty"]
+const symbol = 'aUSDC';
+const amount = 2000000;
+
+(async () => {
+    const wallet = new Wallet(
+        fantom.privateKey,
+        new JsonRpcProvider(fantom.url),
+    );
+
+    const multiSend = new Contract(contract, MultiSend.abi, wallet);
+    const usda = new Contract(tokenAddr, IERC20.abi, wallet);
+
+    console.log(`wallet has ${(await usda.balanceOf(wallet.address)) / 1e6} ${symbol} balance`)
+    console.log(`gateway is ${(await multiSend.gateway())}`)
+
+    const approveTx = await usda.approve(multiSend.address, amount);
+    try {
+        const approved =  await approveTx.wait();
+        console.log("Tx is approved on ",`https://testnet.ftmscan.com/tx/${approved.transactionHash}`)
+    } catch (e) {
+        console.log("err at approve ", e)
+    }
+
+    try {
+        const sendTx = await multiSend.multiSend(destChain, destAddress, receiver, symbol, amount, {
+            value: ethers.utils.parseEther('0.01'),
+        });
+        const tx = await sendTx.wait();
+        console.log(`transaction hash is ${tx.transactionHash}`);
+        console.log("Tx is approved on ",`https://testnet.axelarscan.io/gmp/${tx.transactionHash}`)
+
+    } catch (e) {
+        console.log("Error sent tx ", e)
+    }
+})();
+```
+
+### Execute the code
+
+```bash
+$ node interact-umee.js 
+wallet has 488.85 aUSDC balance
+gateway is 0x97837985Ec0494E7b9C71f5D3f9250188477ae14
+Tx is approved on  https://testnet.ftmscan.com/tx/0x5f13fd087c5aebbeed073f4ee6e16faffbb12e289d7f0e0289c99fffc7299e69
+transaction hash is 0x811795d093273036bd7c7cd984b0805b17f80310b0c52fb2d5c2b58a62dfbfb1
+Tx is approved on  https://testnet.axelarscan.io/gmp/0x811795d093273036bd7c7cd984b0805b17f80310b0c52fb2d5c2b58a62dfbfb1
+```
+
+> You will get 2 USDC from fantom to umee receiver address
+
+### Tested on `canon-4` network
+
+Received  by [umee1grechyg9el4fp36vk4typzrwyfqk4cpemmy6ya](https://canon-4.api.network.umee.cc/cosmos/bank/v1beta1/balances/umee1grechyg9el4fp36vk4typzrwyfqk4cpemmy6ya)
+
+IBC Denom trace : [6F34E1BD664C36CE49ACC28E60D62559A5F96C4F9A6CCE4FC5A67B2852E24CFE](https://canon-4.api.network.umee.cc/ibc/apps/transfer/v1/denom_traces/6F34E1BD664C36CE49ACC28E60D62559A5F96C4F9A6CCE4FC5A67B2852E24CFE)
+
+Axelar GMP Txn: [0x332ee321c3d18435e440f0b814ecc153c6904922bc8af957ff93c13dc677ecce](https://testnet.axelarscan.io/gmp/0x332ee321c3d18435e440f0b814ecc153c6904922bc8af957ff93c13dc677ecce)
+
+FTM Txn : [0x56116dfb03df5a1dc46e767380c26dd32db68469e64b05d46be8cd6a2d03dcb1](https://testnet.ftmscan.com/tx/0x56116dfb03df5a1dc46e767380c26dd32db68469e64b05d46be8cd6a2d03dcb1)