group_policy_address is the account address of group policy.
proposersstring[]
proposers are the account addresses of the proposers.
Proposers signatures will be counted as yes votes.
metadatastring
metadata is any arbitrary metadata attached to the proposal.
exec'EXEC_UNSPECIFIED' | 'EXEC_TRY'
exec defines the mode of execution of the proposal,
whether it should be executed immediately on creation or not.
If so, proposers signatures are considered as Yes votes.