[7.0] Add defaults for mappings

[PaintNinja]

As of Minecraft 26.1, it is no longer being obfuscated. Additionally, Forge has been using official mappings by default in MDKs since 1.17.1 (or partially in 1.16.5 - MCP classnames with MojMap fields and methods).

FG7 currently supports Parchment and Official mappings. With 26.1 no longer being obfuscated meaning param names are also included, it's unclear if Parchment will continue to be maintained on newer versions going forward as the only remaining benefit is javadocs, which is one of their weaknesses.

I'd like to request a small QoL feature - default to mappings channel: 'official', version: minecraftVersion, as least for 1.14.4+ where MojMap is available and a stable target (unlike Parchment which theoretically can later add more mappings on the same MC release). If grabbing the MC version from the minecraft.dependency(...) part is too tricky, having just the channel default to official would be okay too.

[Jonathing]

This requires bringing in the Forge -> MC version logic from Mavenizer. But it can be done.

[LexManos]

It should be as simple as parsing the version for >= MC 1.14.4
Making 'official' the default for anything official exists for makes sense to me.

I'm also okay with making the version optional, specifically for 'official' as I do not see a good case for supporting using the official mappings on mismatched versions (1.14.4's map on 1.20.1 would be weird)

Internally we would still need to version it, But mavenizer already knows how to add the version.
If we exposed the exact mapping key in the 'output json', like we talked about before, it'd let us simplify/remove the parchment logic in FG as well.

Thinking about it, we could probably get away with removing the version for parchment as well as just finding the latest version in mavenizer. Tho there is one concern, does Mixin support targeting by parameter names? As that is the only functional place parchment versions would vary.

If it doesn't then parchment is just 'latest set of javadocs' and not a functional mapping set. Which means modders wouldn't care about the version they basically want a 'javadocs = on' flag.

That may be a stupid idea, but figured i'd voice it.

[PaintNinja]

For Parchment, I think it's safe to assume that if they specify only mappings channel: 'parchment' without a version, they always want the latest one for their MC version. People relying on Parchment names being consistent should explicitly lock in a version for reproducible builds.

[Jonathing]

Mixin does support targeting parameters by name. You should never do it, but you can.

I've already made my reservations about making default behaviors for aspects of the build that could change, with the Parchment version being one such aspect. But, if that's something you want us to add, I won't stop you.

[LexManos]

Mixin does support targeting parameters by name. You should never do it, but you can.

Damn, oh well. In that case ya, For mappings that CAN change {parchment} locking the version makes sense.
It was just an idea.

I think it'd probably be good enough to just default to official.