Add EIP: Financial Bonds (ethereum#7092)

* Add financial bonds draft

* Update eip-financial_bonds.md

* Update and rename eip-financial_bonds.md to eip-7092.md

* Add embedded options logic

* Update eip-7092.md

* Update eip-7092.md

* change disapprove functions to decreaseAllowance functions

* Update eip-7092.md

* update to RECOMMENDED

* change IERC to IERC7092

* change event Disapprove to AllowanceDecreased

* Create ERC7092.sol in the assets folder

* Move eip-7092 in EIPS folder

* Rename eip-7092 to eip-7092.md

* Create IERC7092.sol

* Create BondStorage.sol

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* updates ref

* Update ref

* remove md file in the EIP root

* change disapprove to decreaseAllowance

* Update eip-7092.md

* Create CouponMath.sol

* change EIP to EIP7092 in CouponMath.sol

* Update BondStorage.sol

* Update embedded options functions

* Update ERC7092.sol

* Update BondStorage.sol

* Update contracts with embeded options

* wip

* fix a couple of typos

As proposed by @fosgate29

* change transfers functions to return a boolean

* change _transfer function to return a bioolean

* implement a third level heading for bonds embedded options title

* update specs

* update motivation

* update rational

* update

* Update eip-7092

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* update rationale

* return boolean for approve function

* Update eip-7092.md

* return boolean to approve and decrease allowance

* Update ERC7092.sol

* Update Rationale

* Update

* Update eip-7092

* Add optional key

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* Update ERC7092.sol

* Update eip-7092.md

* Update eip-7092.md

* Update eip-7092.md

* add totalSupply and balanceOf in BondStorage

* add totalSupply and balanceOf functions

* add totalSupply and balanceOf functions

* remove totalSupply and balanceOf in bondStorage - already defined in ERC contract

* Update eip-7092.md

* Update CouponMath.sol

* update text: replace tracker by explorer

* add link to etherscan

* remove link: not supported

* update the eip-7092 according to comments from @lightclient

* keep backward compatibility as sub-sub-section for tests to pass

* Update EIPS/eip-7092.md

Co-authored-by: lightclient <[email protected]>

* Update eip-7092.md

* UIpdarte the Backward Compatibility to appear as a section

* Update assets/eip-7092/IERC7092.sol

Co-authored-by: lightclient <[email protected]>

* Update assets/eip-7092/ERC7092.sol

Co-authored-by: lightclient <[email protected]>

* Update assets/eip-7092/BondStorage.sol

Co-authored-by: lightclient <[email protected]>

* Update CouponMath.sol

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Co-authored-by: lightclient <[email protected]>