Implement three trace APIs (#2205)

* Implement three trace APIs:

- trace_block
- trace_filter
- trace_transaction

Plus tests and docs

* Fix for PR comment regarding trace_filter pagination

- Moved pagination earlier in the code to avoid unnecessary traces
- I've taken a procedural approach here with use of a loop label, but I'm open to switching to iterators

* Removed some redundant code and comments

* Fix for trace_transaction return type and test

docs/api/trace/trace_block.doc.md

@@ -0,0 +1,63 @@
+# Title
+
+trace_block
+
+# Keywords
+
+block,trace,parity
+
+# Description
+
+Returns traces created at given block. The traces are returned in transaction index order.
+
+# Curl
+
+```shell
+curl -d '{
+"id": "1",
+"jsonrpc": "2.0",
+"method": "trace_block",
+"params": ["0x2ed119"]
+}' -H "Content-Type: application/json" -X POST "{{ _api_url }}"
+```
+
+# Response
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": [
+    {
+      "output": "0x",
+      "stateDiff": null,
+      "trace": [{
+        "action": {
+          "from": "0x1c39ba39e4735cb65978d4db400ddd70a72dc750",
+          "gas": "0x0",
+          "value": "0x1",
+          "callType": "call",
+          "to": "0x2910543af39aba0cd09dbb2d50200b3e800a63d2"
+        },
+        "result": {
+          "gasUsed": "0x0",
+          "output": "0x"
+        },
+        "subtraces": 0,
+        "traceAddress": [],
+        "type": "call"
+      }],
+      "vmTrace": null
+    }
+  ]
+}
+```
+
+# Arguments
+
+| Parameter | Type   | Required | Description                     |
+|-----------|--------|----------|---------------------------------|
+| `id`      | string | Required | `"1"`                          |
+| `jsonrpc` | string | Required | `"2.0"`                        |
+| `method`  | string | Required | `"trace_block"`                |
+| `params`  | array  | Required | `[blockNumber]` Block number or tag |

docs/api/trace/trace_filter.doc.md

@@ -0,0 +1,79 @@
+# Title
+
+trace_filter
+
+# Keywords
+
+trace,filter,parity
+
+# Description
+
+Returns traces matching given filter. The traces are returned in transaction index order.
+
+# Curl
+
+```shell
+curl -d '{
+"id": "1",
+"jsonrpc": "2.0",
+"method": "trace_filter",
+"params": [{
+  "fromBlock": "0x2ed119",
+  "toBlock": "0x2ed119",
+  "fromAddress": ["0x1c39ba39e4735cb65978d4db400ddd70a72dc750"],
+  "toAddress": ["0x2910543af39aba0cd09dbb2d50200b3e800a63d2"],
+  "after": 0,
+  "count": 100
+}]
+}' -H "Content-Type: application/json" -X POST "{{ _api_url }}"
+```
+
+# Response
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": [
+    {
+      "output": "0x",
+      "stateDiff": null,
+      "trace": [{
+        "action": {
+          "from": "0x1c39ba39e4735cb65978d4db400ddd70a72dc750",
+          "gas": "0x0",
+          "value": "0x1",
+          "callType": "call",
+          "to": "0x2910543af39aba0cd09dbb2d50200b3e800a63d2"
+        },
+        "result": {
+          "gasUsed": "0x0",
+          "output": "0x"
+        },
+        "subtraces": 0,
+        "traceAddress": [],
+        "type": "call"
+      }],
+      "vmTrace": null
+    }
+  ]
+}
+```
+
+# Arguments
+
+| Parameter | Type   | Required | Description                                          |
+|-----------|--------|----------|------------------------------------------------------|
+| `id`      | string | Required | `"1"`                                               |
+| `jsonrpc` | string | Required | `"2.0"`                                            |
+| `method`  | string | Required | `"trace_filter"`                                   |
+| `params`  | array  | Required | `[filterOptions]` Object containing filter options: |
+
+Filter Options:
+
+- `fromBlock`: `BlockNumber` - (optional) From this block
+- `toBlock`: `BlockNumber` - (optional) To this block
+- `fromAddress`: `[Address]` - (optional) Sent from these addresses
+- `toAddress`: `[Address]` - (optional) Sent to these addresses
+- `after`: `Integer` - (optional) The offset trace number
+- `count`: `Integer` - (optional) Integer number of traces to display in a batch

docs/api/trace/trace_transaction.doc.md

@@ -0,0 +1,73 @@
+# Title
+
+trace_transaction
+
+# Keywords
+
+transaction,trace,parity
+
+# Description
+
+Returns all traces of given transaction. The traces are returned in transaction index order and each trace object has the following format.
+
+# Curl
+
+```shell
+curl -d '{
+"id": "1",
+"jsonrpc": "2.0",
+"method": "trace_transaction",
+"params": ["0x17104ac9d3312d8c136b7f44d4b8b47852618065ebfa534bd2d3b5ef218ca1f3"]
+}' -H "Content-Type: application/json" -X POST "{{ _api_url }}"
+```
+
+# Response
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": {
+    "output": "0x",
+    "stateDiff": {
+      "0x00...01": {
+        "balance": {
+          "*": {
+            "from": "0x100",
+            "to": "0x110"
+          }
+        },
+        "code": "=",
+        "nonce": "=",
+        "storage": {}
+      }
+    },
+    "trace": {
+      "action": {
+        "from": "0x627306090abab3a6e1400e9345bc60c78a8bef57",
+        "gas": "0x1dcd12a0",
+        "value": "0x0",
+        "callType": "call",
+        "input": "0x",
+        "to": "0xf12b5dd4ead5f743c6baa640b0216200e89b60da"
+      },
+      "result": {
+        "gasUsed": "0x0",
+        "output": "0x"
+      },
+      "subtraces": 0,
+      "traceAddress": [],
+      "type": "call"
+    }
+  }
+}
+```
+
+# Arguments
+
+| Parameter | Type   | Required | Description                            |
+|-----------|--------|----------|----------------------------------------|
+| `id`      | string | Required | `"1"`                                  |
+| `jsonrpc` | string | Required | `"2.0"`                               |
+| `method`  | string | Required | `"trace_transaction"`                  |
+| `params`  | array  | Required | `[transactionHash]` Transaction hash   |