More than triple linter speed

[freeqaz]

This makes linting MUCH faster by doing a few things:

• Pointing the TypeScript linter at the source files instead of generated files ("main": "src/foo.ts" instead of "main": "build/foo.js")
  • Results in a 50% improvement (28s -> 15s on my machine)
• Remove the LunaDefend files from the linter type tree
  • Results in another ~50% improvement for me (15s -> 8s)
• Added --cache to the call to ESLint which makes it MUCH faster on commit.

The slow part of the linting is because of the parser: '@typescript-eslint/parser' bit of the .eslintrc.js.

That relies on Typescript to generate the import graph and... yeah, it's really slow.

There is a fork we could use here: https://github.com/un-es/eslint-plugin-i/

But it was throwing an error when I tried it with one of the rules we use, and even though it was faster, this is now fast enough for me.