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

plugins/code/completers/example_completer/provider_response_cache.py

@@ -0,0 +1,113 @@
+# Python imports
+from concurrent.futures import ThreadPoolExecutor
+import re
+
+# Lib imports
+import gi
+gi.require_version('Gtk', '3.0')
+gi.require_version('GtkSource', '4')
+
+from gi.repository import Gtk
+from gi.repository import GLib
+from gi.repository import GtkSource
+
+# Application imports
+from libs.event_factory import Code_Event_Types
+
+from core.widgets.code.completion_providers.provider_response_cache_base import ProviderResponseCacheBase
+
+
+
+class ProviderResponseCache(ProviderResponseCacheBase):
+    def __init__(self):
+        super(ProviderResponseCache, self).__init__()
+
+        # Note: Using asyncio.run causes a keyboard trap that prevents app
+        # closure from terminal. ThreadPoolExecutor seems to not have such issues...
+        self.executor = ThreadPoolExecutor(max_workers = 1)
+        self.matchers: dict = {
+            "hello": {
+                "label": "Hello, World!",
+                "text": "Hello, World!",
+                "info": GLib.markup_escape_text( "<b>Says the first ever program developers write...</b>" )
+            },
+            "foo": {
+                "label": "foo",
+                "text": "foo }}"
+            },
+            "bar": {
+                "label": "bar",
+                "text": "bar }}"
+            }
+        }
+
+
+    def process_file_load(self, event: Code_Event_Types.AddedNewFileEvent):
+        ...
+
+    def process_file_close(self, event: Code_Event_Types.RemovedFileEvent):
+        ...
+
+    def process_file_save(self, event: Code_Event_Types.SavedFileEvent):
+        ...
+
+    def process_file_change(self, event: Code_Event_Types.TextChangedEvent):
+        ...
+
+    def filter(self, word: str) -> list[dict]:
+        ...
+
+    def filter_with_context(self, context) -> list[dict]:
+        """
+            In this instance, it will do 2 things:
+                1) always provide Hello World! (Not ideal but an option so its in the example)
+                2) Utilizes the Gtk.TextIter from the TextBuffer to determine if there is a jinja
+                    example of '{{ custom.' if so it will provide you with the options of foo and bar.
+            If selected it will insert foo }} or bar }}, completing your syntax...
+
+            PLEASE NOTE the GtkTextIter Logic and regex are really rough and should be adjusted and tuned
+        """
+
+        proposals: list[dict] = [
+            {
+                "label": self.matchers[ "hello" ]["label"],
+                "text":  self.matchers[ "hello" ]["text"],
+                "info":  self.matchers[ "hello" ]["info"]
+            }
+        ]
+
+        # Gtk Versions differ on get_iter responses...
+        end_iter = context.get_iter()
+        if not isinstance(end_iter, Gtk.TextIter):
+            _, end_iter = context.get_iter()
+
+        if not end_iter: return
+
+        buf = end_iter.get_buffer()
+        mov_iter = end_iter.copy()
+        if mov_iter.backward_search('{{', Gtk.TextSearchFlags.VISIBLE_ONLY):
+            mov_iter, _ = mov_iter.backward_search('{{', Gtk.TextSearchFlags.VISIBLE_ONLY)
+            left_text = buf.get_text(mov_iter, end_iter, True)
+        else:
+            left_text = ''
+
+        if re.match(r'.*\{\{\s*custom\.$', left_text):
+            # optionally proposed based on left search via regex
+            proposals.append(
+                {
+                    "label": self.matchers[ "foo" ]["label"],
+                    "text":  self.matchers[ "foo" ]["text"],
+                    "info":  ""
+                }
+            )
+
+            # optionally proposed based on left search via regex
+            proposals.append(
+                {
+                    "label": self.matchers[ "bar" ]["label"],
+                    "text":  self.matchers[ "bar" ]["text"],
+                    "info":  ""
+                }
+            )
+
+        return proposals