[analyzer] Allow matching non-CallExprs using CallDescriptions

Fallback to stringification and string comparison if we cannot compare
the `IdentifierInfo`s, which is the case for C++ overloaded operators,
constructors, destructors, etc.

Examples:
  { "std", "basic_string", "basic_string", 2} // match the 2 param std::string constructor
  { "std", "basic_string", "~basic_string" }  // match the std::string destructor
  { "aaa", "bbb", "operator int" } // matches the struct bbb conversion operator to int

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D111535