[SV] Rename SV passes to reflect that they're SV passes and not HW

[mortbopet]

Essentially everything prefixed with HW in https://github.com/llvm/circt/blob/main/include/circt/Dialect/SV/SVPasses.td.

In the spirit of

1. keeping our codebase ready for the potential addition of new backends in the future
2. avoid confusion about what dialect(s) a pass pertains to

various SV passes should be renamed to reflect that they aren't strictly HW passes. These passes live in the SV directories and they lower HW constructs to SV constructs, hence these are SV passes, and not HW passes.