Fix AST-137779: Move getScansForProject off the UI thread on scan completion

DataProvider.getScansForProject() invokes a blocking CLI subprocess
(CxWrapper.scanList -> Execution.executeCommand -> readLine). Calling it
inside syncExec blocked the UI thread for ~1.9s and caused a deadlock
where pool-9-thread-1 waited on the UI thread that was stuck in I/O.

Fix: read the branch combo text with a minimal syncExec (widget read only,
no I/O), then call getScansForProject on the background pollingScan thread,
then update the combo and show the notification in a second syncExec that
contains no blocking calls.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: cx-aniket-shinde

checkmarx-ast-eclipse-plugin/src/com/checkmarx/eclipse/views/actions/ActionStartScan.java

@@ -334,19 +334,24 @@ private Runnable pollingScan(String scanId) {
 					startScanAction.setEnabled(true);
 
 					if (scan.getStatus().toLowerCase(Locale.ROOT).equals(PluginConstants.CX_SCAN_COMPLETED_STATUS)) {
+						// Read branch text on UI thread (fast widget access only).
+						final String[] branchHolder = new String[1];
+						Display.getDefault().syncExec(() -> branchHolder[0] = branchesCombo.getCombo().getText());
+
+						// Fetch scan list on the background thread so the UI is never blocked.
+						List<Scan> scanList = DataProvider.getInstance().getScansForProject(branchHolder[0]);
+
+						// Update UI and show notification on the UI thread (no blocking I/O here).
 						Display.getDefault().syncExec(new Runnable() {
 							AbstractNotificationPopup notification;
 
 							@Override
 							public void run() {
-								// Refresh the scan list and mark the new scan as latest —
-								// but do NOT auto-load results or change the current view.
-								List<Scan> scanList = DataProvider.getInstance().getScansForProject(branchesCombo.getCombo().getText());
 								GlobalSettings.storeInPreferences("LATEST_SCAN_ID", scanId);
 								scansCombo.setInput(scanList);
 
-								// Show notification. Results only load when the user explicitly
-								// clicks "Load Results"; closing/ignoring leaves the current view intact.
+								// Results only load when the user explicitly clicks "Load Results".
+								// Closing or ignoring the notification leaves the current view intact.
 								notification = new NotificationPopUpUI(Display.getCurrent(),
 										PluginConstants.CX_SCAN_FINISHED_TITLE,
 										PluginConstants.CX_SCAN_FINISHED_DESCRIPTION, null,