/closes #707 /claim #707

Will add a screencast soon

Description

This PR implements undo and redo functionality in Mudlet’s code editor (edbee widget), addressing [issue #707]. ( The editor is shared across triggers, aliases, scripts, timers, keys, and variables, so the changes apply universally.

Changes

• Added QShortcut for Ctrl+Z (undo) and Ctrl+Y (redo) to the dlgTriggerEditor constructor, connected to the edbee TextEditorController’s undo/redo methods.
• Added “Undo” and “Redo” actions to the editor’s context menu (right-click in the code area), with icons and connections to the same methods.
• Ensured shortcuts have WidgetWithChildrenShortcut context for proper focus handling.

Implementation Details

• The edbee widget (mpSourceEditorEdbee) is shared across all editing areas, so no separate implementations were needed for aliases, scripts, etc.
• Undo/redo works for typing, deletions, insertions, multi-line edits, and selections.
• Context menu integration provides an alternative to shortcuts.
• No regressions expected, as changes are isolated to editor interactions.