feat: add fcli fpr module for local FPR file operations

[SangameshV]

Introduces a new fcli fpr command tree that operates directly on local
.fpr files without requiring an SSC or FoD session.

Commands:

• fcli fpr issue list - List vulnerabilities from an FPR
• fcli fpr issue get - Get full details for a single issue;
  use --embed=history to include
  audit revision, comments, and the
  ClientAuditTrail tag-change history
• fcli fpr issue count - Count issues by category
• fcli fpr issue audit - Audit one or more issues in-place
  via --instance-ids (comma-separated),
  with --analysis, --comment,
  --suppress, and optional --user
  (defaults to the OS username)
• fcli fpr apply-remediations - Apply auto-remediations from an FPR

Implementation details:

• New fcli-fpr Gradle module wired through gradle.properties,
  fcli-app/build.gradle.kts, and FCLIRootCommands.
• Reuses FPR parsing infrastructure from fcli-aviator-common
  (FprHandle, FPRProcessor, StreamingFVDLProcessor, AuditProcessor).
• AuditProcessor extended with:
  • auditIssue() that skips revision bump and TagHistory write when
    the tag value is unchanged (idempotent re-audits).
  • saveAuditXml() is now atomic: serialization happens in memory
    first, so a failed transform never corrupts the FPR.
  • Username is now caller-provided (no more hard-coded default).
• AuditIssue model gained TagHistoryEntry for full audit history.
• --analysis is validated case-insensitively against the canonical
  SSC values and canonicalized in the output.
• Per-issue results report __action__ = AUDITED or UNCHANGED.