Consider replacing webpack with esbuild/rollup for better sourcemaps

[sidvishnoi]

I did a quick (incomplete) test with esbuild, and could get much better sourcemaps than webpack already.

Might make sense to use rollup due to better plugin support, but haven't tested sourcemap quality yet - should be better than what webpack gives already at least.

[sidvishnoi]

Note that we'd need to update awilix container to use PROXY injection, as CLASSIC will fail with esbuild/rollyup (I verified with esbuild and wxt). See my very raw WIP esbuild branch

[sidvishnoi]

Current sourcemaps for example: