fod sast-scan start: add --in-progress-action and --entitlement-preference options, fix NPE

[Copilot]

Addresses two review comments on PR #1015: a potential NullPointerException on the remediationScanType mixin field, and missing functional test coverage for the new advanced-scan code paths.

Changes

FoDSastScanStartCommand

• Added --in-progress-action (InProgressScanActionType) and --entitlement-preference (EntitlementPreferenceType) options
• Routes to startScanAdvanced when either new option is supplied; falls back to startScanWithDefaults otherwise (backward-compatible)
• Guards remediationScanType against null before dereferencing — @Mixin fields are not guaranteed to be injected:

  // Before (NPE risk)
  FoDEnums.RemediationScanPreferenceType remediationPref = remediationScanType.getRemediationScanPreferenceType();
  
  // After
  FoDEnums.RemediationScanPreferenceType remediationPref = remediationScanType != null
          ? remediationScanType.getRemediationScanPreferenceType() : null;

• Translates CancelScanInProgress → "CancelInProgressScan" at the SAST command boundary (FoD's start-scan-advanced rejects the enum name); Queue is the default when the advanced path is taken without an explicit --in-progress-action

FoDScanSastHelper.startScanAdvanced

• Passes inProgressScanActionType as a raw string rather than through valueOf(), since the translated wire value CancelInProgressScan is not a valid enum name; added a comment explaining the intentional asymmetry with the other parameters

FoDMessages.properties

• Added fcli.fod.sast-scan.start.in-progress-action description with completion candidates

FoDScanSpec (ftest)

• Added start.sast-scan-advanced-queue: exercises the advanced endpoint with --in-progress-action=Queue
• Added start.sast-scan-advanced-entitlement-preference: exercises the advanced endpoint with --entitlement-preference=SubscriptionOnly (implicitly defaults --in-progress-action to Queue)