[Clang] Refactor diagnostics for SME builtins. (#78258)

The arm_sme.td file was still using `IsSharedZA` and `IsPreservesZA`,
which should be changed to match the new state attributes added in
#76971.

This patch adds `IsInZA`, `IsOutZA` and `IsInOutZA` as the state for the
Clang builtins and fixes up the code in SemaChecking and SveEmitter to
match.

Note that the code is written in such a way that it can be easily
extended with ZT0 state (to follow in a future patch).

Author: sdesmalen-arm