Implement testing plugin

[dplochcoder]

Implements a testing plugin to enable easier debugging of new mod menu features. Also fixes at least one bug found along the way.

[BadMagic100]

1. Are the git hooks actually working as intended here? I was under the impression it won't work if it's not at the repo root
2. Fwiw it's easier to review the inter-revision diff if you don't force push, I'll usually end up squashing anyway

[dplochcoder]

1. Are the git hooks actually working as intended here? I was under the impression it won't work if it's not at the repo root

It's never worked for me so idk, I've resorted to running csharpier manually.

2. Fwiw it's easier to review the inter-revision diff if you don't force push, I'll usually end up squashing anyway

Done.

[BadMagic100]

On 1, the way to know would be to check if your commit is taking seconds instead of milliseconds (running the build). I can do a spot check on it this evening though

[BadMagic100]

looks like it works. It was easy to verify

$ git commit --allow-empty -m "check precommit"
[Husky] 🚀 Loading tasks ...
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[Husky] ⚡ Preparing task 'Format and build'
[Husky] ⌛ Executing task 'Format and build' ...
...