Don't offer partial fix-its for `modernize-pass-by-value`

This commit improves the fix-its of modernize-pass-by-value by
no longer proposing partial fixes. In the presence of using/typedef,
we failed to rewrite the function signature but still adjusted the
function body. This led to incorrect, partial fix-its. Instead, the
check now simply doesn't offer any fixes at all in such a situation.