Improve error message for range in match

Range allows char and numeric types, but previous error message
mentioned only numeric types.
auto merge of #14743 : Sawyer47/rust/range-msg, r=huonw

Range allows char and numeric types, but previous error message
mentioned only numeric types.
Provide a witness pattern for non-exhaustive patterns

Fixed #4321
Check pattern refutability the same way exhaustiveness is checked
Add support for fixed size vectors in let/arg patterns

Fixes #7784
Add unreachability detection for missized patterns of fixed size vectors

Fixed #13482
Update tests with the new error messages