Add zstd Compressor

[solonovamax]

Closes #10014

↪️ Pull Request

Adds a zstd compressor, as described in #10014.

I have chosen not to enable this by default, as zstd performs worse than brotli.

💻 Examples

Usage is the same as the brotli and gzip compressors, in your .parcelrc:

 {
   "extends": ["@parcel/config-default"],
   "compressors": {
-    "*": ["...", "@parcel/compressor-gzip", "@parcel/compressor-brotli"]
+    "*": ["...", "@parcel/compressor-gzip", "@parcel/compressor-brotli", "@parcel/compressor-zstd"]
   }
 }

🚨 Test instructions

Tests included as integration tests.

✔️ PR Todo

• Added/updated unit tests for this change
• Filled out test instructions (In case there aren't any unit tests)
• Included links to related issues/PRs