Moved plugins and refactor command system

- Moved plugins to apropriate sub folders
- Refactor command system with new add_command method and rename GetCommandSystemEvent to GetNewCommandSystemEvent
- Add RegisterCommandEvent for dynamic command registration
- Change footer container orientation to VERTICAL
- Add search-highlight tag to source buffer
- Add file change detection (deleted, externally modified) in source_file
- Add JSON prettify option to source view popup menu
- Enable hexpand on VTE widget
- Update plugins_controller_mixin to use widget_registry

src/libs/dto/code/__init__.py

@@ -5,8 +5,9 @@
 
 from .code_event import CodeEvent
 from .register_provider_event import RegisterProviderEvent
+from .register_command_event import RegisterCommandEvent
 
-from .get_command_system_event import GetCommandSystemEvent
+from .get_new_command_system_event import GetNewCommandSystemEvent
 from .request_completion_event import RequestCompletionEvent
 from .cursor_moved_event import CursorMovedEvent
 from .modified_changed_event import ModifiedChangedEvent

src/libs/dto/code/get_new_command_system_event.py

@@ -9,5 +9,5 @@ from .code_event import CodeEvent
 
 
 @dataclass
-class GetCommandSystemEvent(CodeEvent):
+class GetNewCommandSystemEvent(CodeEvent):
     ...

src/libs/dto/code/register_command_event.py

@@ -0,0 +1,20 @@
+# Python imports
+from dataclasses import dataclass, field
+
+# Lib imports
+import gi
+gi.require_version('GtkSource', '4')
+
+from gi.repository import GtkSource
+
+# Application imports
+from ..base_event import BaseEvent
+
+
+
+@dataclass
+class RegisterCommandEvent(BaseEvent):
+    command_name: str = ""
+    command: callable = None
+    binding_mode: str = ""
+    binding: str      = ""