Feat: polls

[elisaado]

Description

My branch aims to fully implement polls as described in https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/3381-polls.md

As it currently stands, it contains a very crude implementation that can display polls, their outcome, and the user's own vote, but does not allow for voting.

The aim is to allow voting, fix the existing TODOs, improve the UI, polish the code (e.g. the big reduce blocks), and add a button to "open"-type polls to view who voted for what.

Fixes #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[elisaado]

I have read the CLA Document and I hereby sign the CLA