feat: Convert to monorepo

[timfish]

This PR:

• Converts to a monorepo - Closes Turn this repo into a monorepo with multiple packages #14
• Add biome to lint and format - Closes Add linting #15
• Changes the test utils to no longer use output filenames in assertions. Output file names can have hashes in them and can change between bundler versions or edits to the test files which makes the tests harder to maintain. Now we just assert the correct number of files and that they contain the correct magic comments
• Adds a test for the CLI to ensure that it can correctly add debug IDs to our all our build output