rule to detect unnecessary quoted types

[DetachHead]

foo: "int" = 1 # error: quotes are not necessary (expression is valid at runtime)

from __future__ import annotations

foo: "Foo & Bar" = 1 # error: quotes are not necessary (invalid runtime expression but __future__.annotations is imported)

from __future__ import annotations

foo: "Foo" # error: quotes are not necessary (type referenced before definition but __future__.annotations is imported)

class Foo:
    ...