Recursively return all the generated files

[keynmol]

Use FileFunction mechanism to more accurately cache the input and output files of the task, as well as react to file changes for more interactive experience.

This combination seems to remove the issues I was seeing before with Zinc.

[keynmol]

I think this needs a bit more work, as I'm getting

[error] 6 |import smithy4s.syntax._
[error]   |       ^^^^^^^^^^^^^^^
[error]   |       value syntax is not a member of smithy4s

occasionally when modifying a broken compilation unit..

[Baccata]

@keynmol is this ready ?

[keynmol]

I believe so, yes.
It's better than what's currently in main, so that's 1 reason to merge it :)