SI-7777 applyDynamic macro fails for nested application

Interplay between the insertApply desugaring and the invokeDynamic desugarings
is already quite brittle, but the real fun begins when macros crash the party.

The proposed patch enriches the `isDesugaredApply` check performed in
`mkInvoke`, the invokeDynamic desugarer, and makes sure that everything
is safe and sound in the macroland.