Refactor controller architecture and multi-insert state

- Rename ControllerContext to ControllerMessageBus for clarity
- Switch ControllerBase to use SingletonRaised
- Replace MarkEventsMixin with MarkerManager for multi-cursor editing
- Add populate_popup event support for source view context menus
- Remove unused swap file events
- Moved JSON prettify feature to plugin
- Fix event name: "removed_file" -> "remove_file"

src/libs/dto/states/__init__.py

@@ -4,4 +4,3 @@
 
 from .source_view_states import SourceViewStates
 from .cursor_action import CursorAction
-from .move_direction import MoveDirection

src/libs/dto/states/move_direction.py

@@ -1,15 +0,0 @@
-# Python imports
-from enum import Enum
-
-# Lib imports
-
-# Application imports
-
-
-
-class MoveDirection(Enum):
-    NONE  = 0
-    UP    = 1
-    DOWN  = 2
-    LEFT  = 3
-    RIGHT = 4