Add ability to debug additional registers via gdb

[jsturtevant]

This pull request adds support for reading and writing XMM and MXCSR registers in the GDB debug interface for all supported hypervisors (KVM, MSHV, and WHVP). It introduces new fields to the register structures to hold these values and implements the necessary logic to fetch and store them using each hypervisor's API.

Register structure updates:

• Added xmm: [u128; 16] and mxcsr: u32 fields to the X86_64Regs struct to store XMM registers and MXCSR control state.

Todo:

• implement set registers
• Test on all the platforms.
  • kvm
  • mshv
  • hyperv

[dblnz]

Thanks for improving the debugging experience. I left some small comments here and there.

[jsturtevant]

I've updated to gdb related tests to work on Windows. This does require it to be installed on the runner vm's which is in progress. Will mark ready for review once that is complete