feat: switch Knip entry and project to Addons

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🚀 Feature: Allow overriding Knip entry #2147
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Goes a bit beyond #2147's original intended scope of entry by also making project an Addon. This way, blockTypeScript and blockVitest fully communicate all file globs to blockKnip.

Also expands blockKnip's intake to read both of those new Addon properties. This will allow customizations such as https://github.com/JoshuaKGoldberg/refined-saved-replies's entry: ["src/content-script.ts"] to be inferred.

🎁

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.82%. Comparing base (0dfbac0) to head (d250000).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2150   +/-   ##
=======================================
  Coverage   99.82%   99.82%           
=======================================
  Files         130      130           
  Lines        5570     5583   +13     
  Branches      401      402    +1     
=======================================
+ Hits         5560     5573   +13     
  Misses         10       10           

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[github-actions]

🎉 This is included in version v2.29.0 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀