gstwebrtc-api: Patch webrtc-adapter to fix Safari behaviour

There's currently a Safari-side bug causing webrtc-adapter to be unable to correctly shim the empty-candidate scenario
which we're using. This patch is very much a workaround and should be removed as soon as Safari and/or webrtc-adapter
fixes this on their side.

https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/issues/439
https://github.com/webrtcHacks/adapter/issues/1140

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1377>

net/webrtc/gstwebrtc-api/package.json

@@ -49,6 +49,7 @@
     "webpack-dev-server": "4.15.1"
   },
   "dependencies": {
+    "patch-package": "8.0.0",
     "webrtc-adapter": "8.2.3"
   },
   "scripts": {
@@ -59,6 +60,7 @@
     "make": "npm run check && npm run build && npm run docs",
     "test": "mocha --node-env=test --exit",
     "prepack": "npm run test && npm run make",
-    "start": "webpack serve"
+    "start": "webpack serve",
+    "postinstall": "patch-package"
   }
 }

net/webrtc/gstwebrtc-api/patches/webrtc-adapter+8.2.3.patch

@@ -0,0 +1,13 @@
+diff --git a/node_modules/webrtc-adapter/src/js/common_shim.js b/node_modules/webrtc-adapter/src/js/common_shim.js
+index 96d7c8e..063ea64 100644
+--- a/node_modules/webrtc-adapter/src/js/common_shim.js
++++ b/node_modules/webrtc-adapter/src/js/common_shim.js
+@@ -388,7 +388,7 @@ export function shimAddIceCandidateNullOrEmpty(window, browserDetails) {
+   }
+   const nativeAddIceCandidate =
+       window.RTCPeerConnection.prototype.addIceCandidate;
+-  if (!nativeAddIceCandidate || nativeAddIceCandidate.length === 0) {
++  if (!nativeAddIceCandidate) {
+     return;
+   }
+   window.RTCPeerConnection.prototype.addIceCandidate =