Add support for the Zvksed extension

[charmitro]

Implements the Zvksed (ShangMi Suite: SM4 Block Cipher) extension, as of version Draft: 20230303

The following instructions are included:

• vsm4k.vi
• vsm4r.[vv,vs]

All instructions were tested with VLEN & ELEN being manually adjusted; results were compared with QEMU results of each instruction.

Current revision is rebased with the latest changes of vector-dev branch.

[charmitro]

Updated the PR:

• Correction on iterating based on the specification
• Correctly Load & Store from/to vector registers

This update is adjusting the implementation to match the Spike implenentation and as a follow-up, ACT Signatures matching.

[charmitro]

Rebased from vector-dev branch.

[github-actions[bot]]

Unit Test Results

712 tests  ±0   712 :heavy_check_mark: ±0   0s :stopwatch: ±0s     6 suites ±0       0 :zzz: ±0      1 files   ±0       0 :x: ±0 

Results for commit f4d9b881. ± Comparison against base commit 58729080.

:recycle: This comment has been updated with latest results.

[Timmmm]

Moved to #848.