Feature/ Add Assessment missing function events

[patitonar]

Context

Fixes #424

Changes proposed in this pull request

Adds events to the stake(), unstake(), withdrawRewards(), withdrawRewardsTo() and castVote() methods.

Used the events already defined in contracts/interfaces/IAssessment.sol. The only event that was updated is the VoteCast event to include the assessment id as a parameter.

Test plan

Unit tests for the corresponding events were introduced in:

• test/unit/Assessment/stake.js
• test/unit/Assessment/unstake.js
• test/unit/Assessment/withdrawRewards.js
• test/unit/Assessment/withdrawRewardsTo.js
• test/unit/Assessment/castVotes.js

Checklist

• Rebased the base branch
• Attached corresponding Github issue
• Prefixed the name with the type of change (i.e. feat, chore, test)
• Performed a self-review of my own code
• Followed the style guidelines of this project
• Made corresponding changes to the documentation
• Didn't generate new warnings
• Didn't generate failures on existing tests
• Added tests that prove my fix is effective or that my feature works

Review

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• 🍰 = Nice to have but not essential.
• 💡 = Suggestion or a comment based on personal opinion
• 🔨 = I believe this should be changed.
• 🤔 = I don’t understand something, do you mind giving me more context?
• 🚀 = Feedback

[danoctavian]

Small changes required

Otherwise looks good

[danoctavian]

LGTM