[AArch64][SVE2] Add the SVE2.1 dupq and extq instructions

This patch adds the assembly/disassembly for the following instructions:

dupq : Broadcast indexed element within each quadword vector segment (unpredicated)
extq : Extract vector segment from each pair of quadword vector segments

The reference can be found here:
https://developer.arm.com/documentation/ddi0602/2022-09

Differential Revision: https://reviews.llvm.org/D137568