feat: add reorder_dimension_by_tunables!, ensure tunable_parameters is correctly ordered

[AayushSabharwal]

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Add any other context about the problem here.

[ChrisRackauckas]

@isaacsas @TorkelE note this does break a Catalyst test which assumed a parameter order. But now there's more guarantees at least on the order of the tunables, see the docs changes.