Allows annotating types with a qualifier

[evant]

@Inject(@Qualifier("a") a: String)

and

@Inject(a: @Qualifier("a") String)

are equivalent.

For now, only annotating the outer type (no type args) is supported.

This lays the groundwork for allowing

typealias A = @Qualifier("a") String

to work in the future when typealias no longer work as a qualifier by itself.

Relates to #253