feat: rage quit

[addyxvii]

Motivation

This feature gives a contributor to a party the ability to rage quit(withdraw 100% of their contribution) before a crowdfund is finalized.

Solution

A rageQuit function has been created that increases a new variable totalContributionsWithdrawn, and removes the _contributionsByContributor mapping for the user who quit. The function also returns the quitting user's total contribution from the crowdfund.

previousTotalContributionsWithdrawn has been added to the Contribution struct for proper accounting in the _getFinalContribution function

[height]

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[0xble]

Thanks for this! I'll review this tomorrow

[0xble]

Nice!

Just run yarn lint and commit changes to fix formatting. 😊