[ARRDT] Port ts-loader transform to native webpack plugin.

[alloy]

It would be ideal if our transformer was webpack loader agnostic and not add extra parsing/printing overhead.

For instance, TMP wants to use esbuild-loader instead of ts-loader (and esbuild doesn't have any way to hook in a transformer).

Example plugin that hooks into webpack's native AST is https://github.com/webpack/webpack/blob/fde018300aa52262c384e937c408d5dd97d62951/lib/UseStrictPlugin.js