Refactor Kernel to extract related code into Foundation classes

[caendesilva]

"When one class does the work of two, awkwardness results."

The goal of this experiment is to extract related code from the HydeKernel, without changing end usage. I'm doing this by creating new foundation classes, and redirecting method calls to them.

This is a rather weird pattern, but it separates logic by concerns, without changing the user experience, which I like.

If this is something that works out, each foundation class should have a test, and a contract (that both the class and the kernel implement)

[codecov]

Codecov Report

Merging #297 (cea6cac) into master (a91c753) will not change coverage.
The diff coverage is 100.00%.

❗ Current head cea6cac differs from pull request most recent head 32ae9e0. Consider uploading reports for the commit 32ae9e0 to get more accurate results

@@             Coverage Diff             @@
##              master      #297   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
- Complexity       815       831   +16     
===========================================
  Files             97        99    +2     
  Lines           2044      2078   +34     
===========================================
+ Hits            2044      2078   +34     

Impacted Files	Coverage Δ
packages/framework/src/Foundation/Filesystem.php	100.00% <100.00%> (ø)
packages/framework/src/Foundation/Hyperlinks.php	100.00% <100.00%> (ø)
packages/framework/src/HydeKernel.php	100.00% <100.00%> (ø)

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[caendesilva]

Since all the tests are so scattered into unit tests it's hard to migrate all of them, so I expect there to be some mess as I can't really migrate everything right now. A lot of these are also very old from when I first started learning PHPUnit/Pest, and aren't that great to be honest.

Edit, at least some methods have links to the unit tests! Gonna make it a lot easier.