C-WCOW: Unify data structures and reuse for C-LCOW and C-WCOW

[MahatiC]

• This change repurposes existing data structures and uses them for both C-LCOW and C-WCOW

[MahatiC]

@anmaxvl Could you review this PR too?

[anmaxvl]

@MahatiC , I think we should have something like this in the end:

pkg/
└── amdsevsnp/
    ├── report.go
    ├── report_windows.go
    ├── report_linux.go
    └── validate.go

• report.go - platform independent code, the exported attestation report fetching (raw/parsed) methods and all the shared type/struct definitions (you'll dedup a good chunk of internal/pspdriver/pspdriver.go code as well)
• report_windows.go - windows specific code to fetch the report (i.e. pspdriver.go code without the shared type definitions) and any additional windows specific definitions we may need
• report_linux.go - linux specific code to fetch the report (report.go content minus type/struct and IOCTL code)
• validate.go - platform independent host data validation code

[KenGordon]

@helsaawy can this be merged now?

[helsaawy]

one comment, lgtm otherwise

[helsaawy]

one comment, lgtm otherwise