ref: typehints, enum instead of raw string, abc and other (#1)

Full code coverage with annotations, fixing errors in various linters: ruff, wps, etc. Fixing errors in type checkers: ty, mypy, pyright. Formatting and bringing code to a consistent style, applying best practices in various aspects.

src/argenta/app/__init__.py

@@ -1,3 +1,12 @@
-__all__ = ["App"]
+__all__ = [
+    "App",
+    "PredefinedMessages",
+    "DynamicDividingLine",
+    "StaticDividingLine",
+    "AutoCompleter"
+]
 
 from argenta.app.models import App
+from argenta.app.defaults import PredefinedMessages
+from argenta.app.dividing_line.models import DynamicDividingLine, StaticDividingLine
+from argenta.app.autocompleter.entity import AutoCompleter