feat(code): adjust split view shortcut and register text insert event

- Change split pane close shortcut from Ctrl+Shift+W to Alt+\
- Register new TextInsertEvent in event system exports
- Prepare groundwork for handling low-level text insertion events in editor pipeline

plugins/code/commands/split_pane/plugin.py

@@ -55,7 +55,7 @@ class Plugin(PluginCode):
             command_name = "close_split_view",
             command      = _close_split_view,
             binding_mode = "released",
-            binding      = "<Shift><Control>w"
+            binding      = "<Alt>\\"
         )
 
         self.emit_to("source_views", event)

src/libs/dto/code/events/__init__.py

@@ -29,6 +29,7 @@ from .cursor_moved_event import CursorMovedEvent
 from .delete_range_event import DeleteRangeEvent
 from .modified_changed_event import ModifiedChangedEvent
 from .text_changed_event import TextChangedEvent
+from .text_insert_event import TextInsertEvent
 from .text_inserted_event import TextInsertedEvent
 from .focused_view_event import FocusedViewEvent
 from .set_active_file_event import SetActiveFileEvent

src/libs/dto/code/events/text_insert_event.py

@@ -0,0 +1,20 @@
+# Python imports
+from dataclasses import dataclass, field
+
+# Lib imports
+import gi
+
+gi.require_version('Gtk', '3.0')
+
+from gi.repository import Gtk
+
+# Application imports
+from .code_event import CodeEvent
+
+
+
+@dataclass
+class TextInsertEvent(CodeEvent):
+    location: Gtk.TextIter = None
+    text: str              = ""
+    length: int            = 0