Clear breakpoints action (#27254)

This PR adds an action that clears all breakpoints and notifies any
active DAPs.

todo
- [x] Implement clear functionality
- [x] Write an integration test for this

Release Notes:

- N/A *or* Added/Fixed/Improved ...

---------

Co-authored-by: Piotr Osiewicz <peterosiewicz@gmail.com>

crates/workspace/src/workspace.rs

@@ -140,7 +140,8 @@ actions!(
         StepOut,
         StepBack,
         Stop,
-        ToggleIgnoreBreakpoints
+        ToggleIgnoreBreakpoints,
+        ClearBreakpoints
     ]
 );