Diagnostics

[meetmangukiya]

• Caching
• Using the foundry.toml config and remappings #12
• Only recompile sources dependent on the changeset
• Compiling... indication on the extension #15
• Document versioning / sequential job processing / racing conditions dealt with

[meetmangukiya]

Clearing diagnostics is very dumb right now. It tracks all the files it ever pushed the diagnostic for and pushes empty array for all of those that had no results. Would be clearing it every time. Should fix it to something better.