* first pass at convert cosmos coin -> evm msg
* test ConvertCosmosCoinFromERC20 method
* test message server for MsgConvertCosmosCoinFromERC20
* update spec to include MsgConvertCosmosCoinFromERC20
* update changelog
* add CLI command for convert-cosmos-coin-from-erc20
* add test of removed/re-enable denom for convert