Improve prf encryption and large blob import

[JMarkstrom]

Add default parameter sets for FIDO2 blob and PRF cmdlets to auto-create supporting FIDO2 credential.

Add AutoCreate / AutoLookup default parameter sets to Import-YubiKeyFIDO2Blob, Export-YubiKeyFIDO2Blob, and Protect-YubiKeyFIDO2File so that users can round-trip blobs and encrypt files without manually specifying credentials or relying parties. Also isolate credential-resolution into dedicated FIDO2 sessions to prevent stale-session bugs.

Goal: Enable zero-configuration FIDO2 workflows — Import, Export, and Protect all "just work" with a single mandatory parameter, creating or reusing synthetic credentials on demand.

Details

• Import-YubiKeyFIDO2Blob.cs:

  • Add AutoCreate default parameter set requiring only -LargeBlob
  • Auto-create or reuse a "blob-storage" credential (AutoCreateRpId / AutoCreateUsername constants)
  • Add -Force to AutoCreate set to suppress confirmation prompts
  • Move credential lookup, RP resolution, and credential creation to isolated sessions (Phase 1), then use a fresh session for assertion + blob operations (Phase 2)
  • Replace switch with if/else if branching; add SupportsShouldProcess and ConfirmImpact.High
  • Update XML documentation and examples

• ExportYubiKeyFIDO2Blob.cs:

  • Add AutoLookup default parameter set requiring only -OutFile
  • Enumerate RPs to find "blob-storage" (case-insensitive), resolve its first credential, or throw with guidance to use Import-YubiKeyFIDO2Blob
  • Add OutFile to all three parameter sets; add AutoCreateRpId constant
  • Simplify BeginProcessing to always connect to FIDO2 (all sets need it)
  • Update XML documentation and examples

• ProtectYubiKeyFIDO2File.cs:

  • Move AutoCreate credential lookup to an isolated session; create credential via New-YubiKeyFIDO2Credential if none exists
  • Move ByRelyingPartyID resolution to an isolated session
  • Use a fresh session for the assertion, not contaminated by credential creation
  • Update doc block wording ("creating or reusing")