This patch adds the `USING_AK_GLOBALLY` macro which is enabled by
default, but can be overridden by build flags.
This is a step towards integrating Jakt and AK types.
This adds an `AK::ByteReader` to help with that so we don't duplicate
the logic all over the place.
No more `*(const u16*)` and `*(const u32*)` for anyone.
This should help a little with #7060.