Implement voteOnProposal command

[emiliolisk]

What was the problem?

This PR resolves #126 for the dexGovernance module.

How was it solved?

• Added voteOnProposal command in voteOnProposal.ts file.
• Registered command in modules.ts folder.

How was it tested?

• Command verification and execute tests are added in commandVoteOnProposal.spec.ts file.
• All tests are passing.

[codecov]

Codecov Report

Patch coverage is 84.37% of modified lines.

Files Changed	Coverage
.../app/modules/dexGovernance/events/proposalVoted.ts	ø
src/app/modules/dexGovernance/module.ts	50.00%
...p/modules/dexGovernance/commands/voteOnProposal.ts	87.71%
src/app/modules/dexGovernance/schemas.ts	100.00%

📢 Thoughts on this report? Let us know!.

[Daniel-Lightcurve]

What was the problem?

This PR resolves #126 for the dexGovernance module.

How was it solved?

• Added voteOnProposal command in voteOnProposal.ts file.
• Registered command in modules.ts folder.

How was it tested?

• Command verification and execute tests are added in commandVoteOnProposal.spec.ts file.
• All tests are passing.

looks good to me