Typescript codegen for Shims

[namesty]

This PR aims to provide better shims updates and type/build checks using TS.

It organizes shims into a shims directory. Inside of said directory there's a globals directory. There's where all JS global shims live as separate TS files.

Pros

• Type-checking for shims code. If it doesn't build with TS, it will throw.
• Separation of concerns. Each shim lives in its own separate file as its own separate variable
• Easier debugging. Shim behavior can be debugged more easily as you can now intervene the shims code in Typescript, instead of modifying the JS string we had before

Pain points

This is def better than the mega string manipulation we had before, but it's still far from ideal:

Because of how the bundler processes globals + how we inject code into the engine wrap + the need to shim require for the JS engine (instead of shimming just modules):

• Required modules need to be local to the require global. See how axios, fs , etc. are done.
• We require a name mapping of global -> shim variable name. See shims/globals/index.ts

[dOrgJelli]

LGTM!