[analyzer][NFC] Switch to using CallDescription::matches() instead of isCalled()

This patch replaces each use of the previous API with the new one.
In variadic cases, it will use the ADL `matchesAny(Call, CDs...)`
variadic function.
Also simplifies some code involving such operations.

Reviewed By: martong, xazax.hun

Differential Revision: https://reviews.llvm.org/D113591