Add type stubs for mido MIDI library

- Created type stubs for various modules in the mido library including messages, midifiles, parser, ports, sockets, syx, tokenizer, and version.
- Implemented type hints for functions and classes to improve type checking and code clarity.
- Added support for MIDI over TCP/IP in sockets module.
- Included methods for reading and writing SYX files in syx module.
- Enhanced the parser functionality with a dedicated Parser class for MIDI byte streams.
- Established a structure for MIDI file handling with MidiFile and MidiTrack classes.

typings/mido/messages/encode.pyi

@@ -0,0 +1,14 @@
+from collections.abc import Callable
+
+from .specs import MsgDict
+
+_SPECIAL_CASES: dict[str, Callable[[MsgDict], list[object]]]
+
+def encode_message(msg: MsgDict) -> list[int]:
+    """Encode msg dict as a list of bytes.
+
+    TODO: Add type and value checking.
+          (Can be turned off with keyword argument.)
+
+    This is not a part of the public API.
+    """