PORTALS-3347 - Remove barrel files

[nickgros]

Benchmarked pnpm build in ADKP. Main goal is to speed up HMR, so reducing this is not the primary goal:

hyperfine --runs 5 'pnpm build'

main

Benchmark 1: pnpm build
  Time (mean ± σ):     32.612 s ±  0.705 s    [User: 44.917 s, System: 4.776 s]
  Range (min … max):   31.548 s … 33.492 s    5 runs

PORTALS-3347

Benchmark 1: pnpm build
  Time (mean ± σ):     29.688 s ±  1.651 s    [User: 41.446 s, System: 4.341 s]
  Range (min … max):   28.078 s … 31.703 s    5 runs