[analyzer] NFC: Store the pointee/referenced type for dynamic type tracking.

The successfulness of a dynamic cast depends only on the C++ class, not the pointer or reference. Thus if *A is a *B, then &A is a &B,
const *A is a const *B etc. This patch changes DynamicCastInfo to store
and check the cast between the unqualified pointed/referenced types.
It also removes e.g. SubstTemplateTypeParmType from both the pointer
and the pointed type.

Differential Revision: https://reviews.llvm.org/D85752