fixes: https://github.com/coder/internal/issues/1300
Adds brotli and zstd compression to the binary cache. Also refactors coderd's streaming encoding middleware to use the same standard set of compression algorithms, so we have them in one place.
relates to: https://github.com/coder/internal/issues/1300
Refactors the options to the site handler to take the cache directory, rather than expecting the caller to call `ExtractOrReadBinFS` and pass the results.
This is important in this stack because we need direct access to the cache directory for compressed file caching.
relates to: https://github.com/coder/internal/issues/1300
Refactors the bin handler to be a `struct` instead of a handlerfunc. The reason we want this is because we are going to introduce a cache of compressed files, so we need somewhere to put this cache.
relates to: https://github.com/coder/internal/issues/1300
Refactors the site binary handler routines to their own file. The `site.go` was getting pretty long and I want to do some refactoring on how the binary handler works.
This PR is literally just moving code from file to file; at the package level nothing is changed.
Spike Curtis