Add a custom SNS function to approve an NNS proposal

Approves a given NNS proposal. If no strict majority is reached, vote according to the majority opinion.

Proposal to add new NervousSystemFunction:

Function:

NervousSystemFunction { id: 1000, name: "Vote on NNS proposal", description: Some( "Vote yes to a given NNS proposal. If there is no strict majority, vote for the majority outcome.", ), function_type: Some( GenericNervousSystemFunction( GenericNervousSystemFunction { target_canister_id: Some( tsbvt-pyaaa-aaaar-qafva-cai, ), target_method_name: Some( "approve_proposal", ), validator_canister_id: Some( tsbvt-pyaaa-aaaar-qafva-cai, ), validator_method_name: Some( "approve_proposal_validate", ), }, ), ), }