feat: add a simple UI for editing funs

[fras2560]

Checklist

• [x] I have added the appropriate label to this PR ("bug", "feature")
• [x] I have assigned myself to this PR
• [x] I have performed a self-review of my code
• [x] I have tested my changes to the best of my abilities (not just unit tests, but integration/end-to-end tests as well)

Issues closed

Part of #188

Description

• Able to create a fun count
• Able to edit an existing fun count
• Update restx end point to expose the fun_id

Screenshots

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 95.72650% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 94.94%. Comparing base (92866d5) to head (2b2d20e). Report is 3 commits behind head on main.

Files	Patch %	Lines
api/convenor/fun.py	84.84%	5 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #223 +/- ## ======================================== Coverage 94.94% 94.94% ======================================== Files 123 125 +2 Lines 10831 10943 +112 ======================================== + Hits 10283 10390 +107 - Misses 548 553 +5 ``` | [Flag](https://app.codecov.io/gh/Major-League-Summer-Baseball/mlsb-platform/pull/223/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Major-League-Summer-Baseball) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/Major-League-Summer-Baseball/mlsb-platform/pull/223/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Major-League-Summer-Baseball) | `94.94% <95.72%> (+<0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Major-League-Summer-Baseball#carryforward-flags-in-the-pull-request-comment) to find out more.

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