RawBank::end() and RawBank::range() are broken

The recent MR !2994 (merged) exposed a bug (see here) in RawBank::end<T>() and RawBank::range<T>() where sizeof(T) is more than 1. The default for RawBank::range<>() happens to be unsigned int which means that the last 1-3 bytes are potentially lost.

Perhaps T should be hardcoded to char, as generalizing to other types in this place makes little sense.