Implement voteOn Proposal command

[Naureen1lightcurve]

Description

Create a command at the voteOnProposalCommand.ts in the commands folder Implement voteOnProposal command and Implement voteOnProposal command.

Acceptance Criteria

Following unit tests are implemented

• voteOnProposal command returns an error when invalid timestamp such as one that is in the past or not a valid timestamp.
• An error is returned when provided with an invalid voter address.
• Voter is able to choose only one decision at a time.
• An error is returned when voter has less than minimum staked tokens.
• Event EVENT_NAME_PROPOSAL_VOTED is emitted.