Prefer match to nested categories

`T.map(E.fold(` can be replaced with `TE.match`.

Likewise, `TE.fold`/`TE.matchE` can also be `TE.match` if they're a pipe that lifts them into a `Task` at the end. (We used the former to avoid having to do this.)

[Examples](https://github.com/sciety/sciety/commit/2778b654f698a51f0cca4754b179c5c14dad49a8)