[libc++] P0433R2: test that deduction guides are properly SFINAEd away.

[libc++] P0433R2: test that deduction guides are properly SFINAEd away.

Deduction guides for containers should not participate in overload
resolution when called with certain incorrect types (e.g. when called
with a template argument in place of an `InputIterator` that doesn't
qualify as an input iterator). Similarly, class template argument
deduction should not select `unique_ptr` constructors that take a
a pointer.

The tests try out every possible incorrect parameter (but never more
than one incorrect parameter in the same invocation).

Also add deduction guides to the synopsis for associative and unordered
containers (this was accidentally omitted from [D112510](https://reviews.llvm.org/D112510)).

Differential Revision: https://reviews.llvm.org/D112904