Feature: Add process expiration events

[MilGard91]

Context

Issue: #864

Changes proposed in this pull request

Add event when bucket or tranche expires

Test plan

Added tests to check if the event is emitted.

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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• 🔨 = I believe this should be changed.
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• 🚀 = Feedback