Support more arguments in FindFilesBase

[JakkuSakura]

This is an attempt to make FindFiles more useful.

It has not been tested yet

closes #1174

[Fizzadar]

This looks great, huge improvement! Few linting things to fix and this is ready I think.

[JakkuSakura]

Just fixed linting.
one notable change is fname
mypy caught that name is defined in FactBase, thus we can't use name directly

[JakkuSakura]

I'm not sure how to express args: List[str] especially it may contain QuoteString

[JakkuSakura]

finally...
I also managed to enhance the tests to support dict as argument.

[Fizzadar]

Nice! Just the test thing (I'll move and merge if I get to it before you :)).

[Fizzadar]

@JakkuSakura this is really awesome, thank you! Sorry it's taken me so long to review it. I've pushed up a quick fix for the tests (also made a mess on rebase first, but fixed).

[JakkuSakura]

Much appreciated! It's my first PR for pyinfra and the lining has cost me some time, but eventually figured out how to do it properly

[Fizzadar]

Much appreciated! It's my first PR for pyinfra and the lining has cost me some time, but eventually figured out how to do it properly

Would love any comments/ideas/etc on how to make the experience better when contributing 🙏