Embed tree-sitter bits in CLI exe; tidy tree-sitter bindings

[StachuDotNet]

• reduce all of our tree-sitter bindings from 3 projects of many files to just 1 project of 3 files
• embed tree-sitter and tree-sitter-darklang libraries in our darklang CLI exe, for all platforms
  • update Dockerfile and such to cross-plat build tree-sitter (for different OSes and architectures)
  • update LibTreeSitter.fsproj to conditionally include the correct tree-sitter build depending on which OS+arch we're building for
• embed tree-sitter-darklang similarly, cross-building and embedding as needed
• at run-time, for both tree-sitter and tree-sitter-darklang: extract to a temp dir, load, and create delegates for
  • this replaces all of the P/Invokeing we did before. We're no longer able to use P/Invoke because we load the library dynamically (at runtime)