Add ttp dependency and refactor OxiAPI and NodeConfig classes

- Added `ttp` as a dependency in `pyproject.toml` and `uv.lock`.
- Updated `NodeConfig` to store model names in lowercase.
- Refactored `OxiAPI` to always create a new session and added a `close` method.
- Removed unnecessary logging in `Node` class.
- Introduced interfaces for device registration with a new `BaseDevice` class and a `register_parser` function.
- Created initial structure for device models, including a `Mikrotik` parser.

oxi/interfaces/models/__init__.py

@@ -0,0 +1,7 @@
+import importlib
+import pkgutil
+
+package = __package__
+
+for loader, module_name, is_pkg in pkgutil.iter_modules(__path__):
+    importlib.import_module(f"{package}.{module_name}")

oxi/interfaces/models/mikrotik.py

@@ -0,0 +1,5 @@
+from oxi.interfaces import register_parser
+
+
+@register_parser(["routeros", "ros", "mikrotik"])
+class Mikrotik: ...