Avoid errors when running headless

[trancexpress]

This change adjusts several classes to handle headless state, i.e. when the workbench is not available. The respective operations now do nothing without a workbench, instead of throwing exceptions.

Fixes: #2673

[github-actions]

Test Results

    54 files  ±0      54 suites  ±0   35m 29s ⏱️ +42s
 4 667 tests ±0   4 645 ✅ ±0   22 💤 ±0  0 ❌ ±0 
11 895 runs  ±0  11 742 ✅ ±0  153 💤 ±0  0 ❌ ±0 

Results for commit e1f6ffd. ± Comparison against base commit 7f435dc.

♻️ This comment has been updated with latest results.

[eclipse-platform-bot]

This pull request changes some projects for the first time in this development cycle.
Therefore the following files need a version increment:

debug/org.eclipse.debug.ui/META-INF/MANIFEST.MF

An additional commit containing all the necessary changes was pushed to the top of this PR's branch. To obtain these changes (for example if you want to push more changes) either fetch from your fork or apply the git patch.

Git patch

From 621e2b89c99fffc8dbf30051cf4afff2f8dffa51 Mon Sep 17 00:00:00 2001
From: Eclipse Platform Bot <platform-bot@eclipse.org>
Date: Sun, 31 May 2026 15:57:08 +0000
Subject: [PATCH] Version bump(s) for 4.41 stream


diff --git a/debug/org.eclipse.debug.ui/META-INF/MANIFEST.MF b/debug/org.eclipse.debug.ui/META-INF/MANIFEST.MF
index 8c8a0b29b7..489122e563 100644
--- a/debug/org.eclipse.debug.ui/META-INF/MANIFEST.MF
+++ b/debug/org.eclipse.debug.ui/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.debug.ui; singleton:=true
-Bundle-Version: 3.21.0.qualifier
+Bundle-Version: 3.21.100.qualifier
 Bundle-Activator: org.eclipse.debug.internal.ui.DebugUIPlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
-- 
2.54.0

Further information are available in Common Build Issues - Missing version increments.