ui: Migrating from babel to swc for js transpiling

[manojVivek]

This shaves off some 30-50s off the build and lint workflows.

But there is scope to cut down another 15-25s if we migrate all shared package transpiling to swc as well. Right now, I haven't done that as swc strips out all type metadata from the compiled files and this is resulting in some lint errors.
The fix is to do consistent type imports/exports which involve a lot of code changes, so saving for the next phase of improvement.

[alwaysmeticulous]

✅ Meticulous spotted zero visual differences across 373 screens tested: view results.

_{Last updated for commit bfc5167. This comment will update as new commits are pushed.}

[brancz]

Seriously awesome! lgtm