Assignment and Inc/Dec operators wouldn't register as a mutation when Implicit...

Assignment and Inc/Dec operators wouldn't register as a mutation when Implicit Paren Casts were present

Add ignoringParenImpCasts to assignment and inc/dec mutation checks in ExprMutationAnalyzer to fix clang-tidy bug PR45490.
https://bugs.llvm.org/show_bug.cgi?id=45490

Reviewed By: njames93, aaron.ballman, gribozavr2

Differential Revision: https://reviews.llvm.org/D79912