Add attached derive clause formatting

[i-am-the-slime]

Warning

This PR was AI-generated. If that's not okay close it! I'm just trying to make PureScript even nicer

Summary

• Adds formatting for derive (Class), derive newtype (Class), and derive (Class) via Type clauses
• Derive clauses are indented under their parent data/newtype declaration
• Uses Grouped layout so class lists stay on one line when they fit
• All existing tests pass, new snapshot test added

Depends on natefaubion/purescript-language-cst-parser (attached-derive-clauses branch).
Companion to purescript/purescript#4592

[i-am-the-slime]

CI fails because it pulls language-cst-parser from the registry, which doesn't have the new types yet. This will pass once natefaubion/purescript-language-cst-parser#66 is merged and released.