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/__init__.py

@@ -0,0 +1,10 @@
+__all__ = [
+    'App',
+    'Orchestrator',
+    'Router',
+]
+
+
+from argenta.app import App
+from argenta.orchestrator import Orchestrator
+from argenta.router import Router