Add support for MsgVoteWeighted #1435
Description
MsgVoteWeighted is like MsgVote but allows splitting the vote in different options. The protobuf definition is here: https://github.com/cosmos/cosmos-sdk/blob/v0.45.8/proto/cosmos/gov/v1beta1/tx.proto#L66-L78. Implementation should be a pretty straight forward addition. We need a new capability, similar to cosmwasm_1_1.
See https://github.com/cosmos/cosmos-sdk/blob/main/docs/architecture/adr-037-gov-split-vote.md for context.