The _trans macro marks strings for translation but doesn't do anything
at runtime. For that, we need to use a function like GetStringT.

General: Make use of std::erase_if/std::erase where applicable

Just some trivial copies that can be eliminated or turned into moves.

Makes for consistency with the surrounding code.

These aren't necessarily cheap to copy, since a control qualifier will
have around 3 std::strings inside of it, so passing by value can churn
allocations a little bit.

std::regex has a relatively expensive constructor, and these are unchanging regexes.