Add support for specific json-rpc endpoints in rollapp-wasm

[omritoptix]

we need to be able to support basic json rpc calls for being able to use one wallet from the portal as demanded by the prince.

currently the portal requires the following method to be supported from wasm:

wallet_switchEthereumChain
wallet_addEthereumChain
eth_chainId
eth_requestAccounts
personal_sign
accountsChanged
eth_signTypedData_v4
-----------------------
bonus method: 
wallet_watchAsset

We currently import evmos in wasm.
Question is: can we just start the json rpc of evmos in wasm or should we support each method independently? or any other solution?