Improve JFace notification snippets and documentation

[vogella]

Summary

• Fix typo in Snippet001 filename (Notifcation → Notification) and class name
• Fix inconsistent indentation in Snippet084
• Simplify Snippet085 to use the builder API idiomatically instead of creating widgets on a shell and reparenting them
• Add missing Snippet001 to JFaceSnippets.md
• Clean up Notification section in JFaceSnippets.md: remove duplicate links, fix typos, improve descriptions

See #1226

Test plan

• Verify Snippet001, Snippet084, and Snippet085 compile and run correctly
• Verify JFaceSnippets.md renders correctly with new links

[github-actions]

Test Results

   851 files   -  1     851 suites   - 1   55m 19s ⏱️ + 2m 30s
 7 890 tests ± 0   7 647 ✅ ± 0  243 💤 ±0  0 ❌ ±0 
20 080 runs   - 92  19 424 ✅  - 92  656 💤 ±0  0 ❌ ±0 

Results for commit 87b1cc6. ± Comparison against base commit e199306.

♻️ 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:

bundles/org.eclipse.jface.notifications/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 166042d9bedc4d65e8e4b12836404bd5f625b845 Mon Sep 17 00:00:00 2001
From: Eclipse Platform Bot <platform-bot@eclipse.org>
Date: Mon, 23 Mar 2026 17:47:44 +0000
Subject: [PATCH] Version bump(s) for 4.40 stream


diff --git a/bundles/org.eclipse.jface.notifications/META-INF/MANIFEST.MF b/bundles/org.eclipse.jface.notifications/META-INF/MANIFEST.MF
index 3bba7af95c..33542e3f12 100644
--- a/bundles/org.eclipse.jface.notifications/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.jface.notifications/META-INF/MANIFEST.MF
@@ -4,7 +4,7 @@ Bundle-Name: %pluginName
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
 Bundle-SymbolicName: org.eclipse.jface.notifications
-Bundle-Version: 0.8.0.qualifier
+Bundle-Version: 0.8.100.qualifier
 Bundle-RequiredExecutionEnvironment: JavaSE-21
 Export-Package: org.eclipse.jface.notifications,
  org.eclipse.jface.notifications.internal;x-internal:=true
-- 
2.53.0

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

[vogella]

Found an issue in the positioning of the Shell, fixed with #3814

[vogella]

Documentation change, so the Unit test failure is ignored