Add basic internal message model

src/models/msg.py

@@ -0,0 +1,19 @@
+from pydantic import BaseModel, Field
+from datetime import datetime
+from enum import Enum
+
+
+class msg_types(Enum):
+    info = "info"
+    warning = "warning"
+    error = "error"
+
+
+class Msg(BaseModel):
+    msg: str = Field(..., description="Message. Required.", examples=["Hello, world!"])
+    type: msg_types = Field(default=msg_types.info)
+    timestamp: datetime = Field(
+        default_factory=datetime.now().astimezone,
+        description="Timestamp. Defaults to current time.",
+        examples=[datetime.now().astimezone()],
+    )