[Gtk4] Link click support

[akurtakov]

Implement Gtk 4 controllers handling by refactoring the non version dependent parts of Gtk 3 handling into separate methods.

[github-actions]

Test Results (linux)

   94 files  ±0     94 suites  ±0   14m 1s ⏱️ -3s
4 577 tests ±0  4 357 ✅ ±0  220 💤 ±0  0 ❌ ±0 
3 335 runs  ±0  3 266 ✅ ±0   69 💤 ±0  0 ❌ ±0 

Results for commit 8176757. ± Comparison against base commit 20bb38c.

♻️ This comment has been updated with latest results.

[akurtakov]

The test even succeeded on gtk 4 prior to this PR due to the fact that there is synthetic event that thrigger the listener but the native signal was not handled to do so.

[Copilot]

Pull request overview

This PR adds GTK4 click/gesture handling to Link by refactoring the shared hit-testing and selection logic out of the GTK3 event handlers into helper methods, enabling link activation via GTK4 controllers.

Changes:

• Refactor GTK3 button press/release and motion logic into shared handlePress, handleRelease, and handleMotion helpers.
• Add GTK4 gesture press/release handlers to trigger link focus/activation.
• Add GTK4 motion handler to update link hover cursor and selection drag behavior.

[Copilot]

Pull request overview

Adds GTK4 link click/motion support to SWT’s Link widget by refactoring shared pointer-handling logic into helper methods and wiring GTK4 gesture/motion controller callbacks alongside existing GTK3 event handlers.

Changes:

• Refactor GTK3 press/release and motion logic into handlePress, handleRelease, and handleMotion.
• Add GTK4 gesture press/release handlers to trigger link activation.
• Add GTK4 motion handler to update cursor/selection behavior consistently with GTK3.

[Copilot]

Pull request overview

Adds GTK4 link click/motion support in SWT Link by refactoring shared pointer-handling logic out of the GTK3 event callbacks and reusing it from GTK4 controllers.

Changes:

• Refactor GTK3 button press/release logic into shared handlePress(...) / handleRelease(...) helpers.
• Add GTK4 gesture press/release handlers to trigger link activation.
• Add GTK4 motion controller handling and reuse shared hover/drag selection logic.

[Copilot]

Pull request overview

Adds GTK4 link click/motion support to SWT’s Link widget by introducing GTK4 controller handlers and refactoring shared pointer-handling logic into helper methods, keeping GTK3 behavior intact while enabling the GTK4 event path.

Changes:

• Refactors GTK3 button press/release handling into version-agnostic helpers (handlePress, handleRelease).
• Implements GTK4 gesture press/release handlers to trigger link focus/selection.
• Implements GTK4 motion handling and shares hover/drag-selection logic via handleMotion.