[clang] [analyzer] Moving TaintPropagation checker out of alpha (PR #67352)

[Daniel Krupp via cfe-commits]

dkrupp wrote:

@steakhal now the commit is rebased and the results in the description are also refreshed (not broken).

All the earlier problematic reports related to tainted integers (memset, malloc, memcpy ...) are not present now as these were removed from this checker as generic sinks by earlier commits.

Your suggested doc fixes also added.

https://github.com/llvm/llvm-project/pull/67352