⚡️ Maintenance: Refactor WebGear and WebGear RTC shutdown handling

- 🏗️ Replaced deprecated Starlette's `on_shutdown` parameter with an async context manager `lifespan` in WebGear and WebGear_RTC APIs.
- 🚚 Moved shutdown logic for VideoGear and peer RTC connections to this new `lifespan` context manager.
- 📦️ Added new `contextlib` import for using `asynccontextmanager`.

Docs:
- 📝 Update README.md with changes to JPEG compression options
  - ✏️ Replaces deprecated options (`frame_jpeg_quality`, `frame_jpeg_optimize`, `frame_jpeg_progressive`) with their newer equivalents (`jpeg_compression_quality,` `jpeg_compression_fastdct`, `jpeg_compression_fastupsample`) in WebGear usage example.

README.md

@@ -515,9 +515,9 @@ from vidgear.gears.asyncio import WebGear
 # various performance tweaks
 options = {
     "frame_size_reduction": 40,
-    "frame_jpeg_quality": 80,
-    "frame_jpeg_optimize": True,
-    "frame_jpeg_progressive": False,
+    "jpeg_compression_quality": 80,
+    "jpeg_compression_fastdct": True,
+    "jpeg_compression_fastupsample": False,
 }
 
 # initialize WebGear app

vidgear/gears/asyncio/webgear.py

@@ -22,6 +22,7 @@
 import os
 import asyncio
 import inspect
+import contextlib
 import numpy as np
 import logging as log
 from os.path import expanduser
@@ -421,7 +422,7 @@ def __call__(self):
             routes=self.routes,
             middleware=self.middleware,
             exception_handlers=self.__exception_handlers,
-            on_shutdown=[self.shutdown],
+            lifespan=self.__lifespan,
         )
 
     async def __producer(self):
@@ -535,6 +536,14 @@ async def __server_error(self, request, exc):
             )
         )
 
+    @contextlib.asynccontextmanager
+    async def __lifespan(self, context):
+        try:
+            yield
+        finally:
+            # close Video Server
+            self.shutdown()
+
     def shutdown(self):
         """
         Implements a Callable to be run on application shutdown

vidgear/gears/asyncio/webgear_rtc.py

@@ -21,6 +21,7 @@
 # import the necessary packages
 import os
 import time
+import contextlib
 import fractions
 import asyncio
 import logging as log
@@ -531,7 +532,7 @@ def __call__(self):
             routes=self.routes,
             middleware=self.middleware,
             exception_handlers=self.__exception_handlers,
-            on_shutdown=[self.__on_shutdown],
+            lifespan=self.__lifespan,
         )
 
     async def __offer(self, request):
@@ -636,16 +637,17 @@ async def __reset_connections(self, request):
             # if does, then do nothing
             return PlainTextResponse("DISABLED")
 
-    async def __on_shutdown(self):
-        """
-        Implements a Callable to be run on application shutdown
-        """
-        # close Video Server
-        self.shutdown()
-        # collects peer RTC connections
-        coros = [pc.close() for pc in self.__pcs]
-        await asyncio.gather(*coros)
-        self.__pcs.clear()
+    @contextlib.asynccontextmanager
+    async def __lifespan(self, context):
+        try:
+            yield
+        finally:
+            # close Video Server
+            self.shutdown()
+            # collects peer RTC connections
+            coros = [pc.close() for pc in self.__pcs]
+            await asyncio.gather(*coros)
+            self.__pcs.clear()
 
     def shutdown(self):
         """