feat: add inputs for JF version and suggester label

[pfitzseb]

This PR adds two input arguments to the action:

• version: 1.0.54 allows pinning JuliaFormatter.jl to a major, minor, or patch version
• suggestion-label: 'foo' only shows suggestions when that label is on the PR

I've also updated setup-julia to v2.

[hyrodium]

Thank you for the PR!

[domluna]

@hyrodium if this looks good to you I'm happy to merge, assuming it's ready @pfitzseb

[pfitzseb]

I tweaked the implementation a bit, so this is good to go from my end.

Note that this is a breaking change: Currently, unformatted files that are not touched by the PR will not cause the action to fail (because reviewdog can't annotate them).

[domluna]

Note that this is a breaking change: Currently, unformatted files that are not touched by the PR will not cause the action to fail (because reviewdog can't annotate them).

could you add a note in the README?

[pfitzseb]

We get an auto-generated changelog, right? Not sure if a note in the readme is necessary in addition to that.

[domluna]

fair enough 👍 merging this now

[pfitzseb]

one sec, I'll squash the commits

[domluna]

I merge with squash and merge but if you wanna remove some history sure go ahead

[pfitzseb]

Yeah, I mainly wanted to mention the breaking nature of this in the commit message. Should be good to go now :)