Implement MSC3819: Allowing widgets to send/receive to-device messages (#8885)

* Implement MSC3819: Allowing widgets to send/receive to-device messages

* Don't change the room events and state events drivers

* Update to latest matrix-widget-api changes

* Support sending encrypted to-device messages

* Use queueToDevice for better reliability

* Update types for latest WidgetDriver changes

* Upgrade matrix-widget-api

* Add tests

* Test StopGapWidget

* Fix a potential memory leak

package.json

@@ -94,7 +94,7 @@
     "matrix-encrypt-attachment": "^1.0.3",
     "matrix-events-sdk": "^0.0.1-beta.7",
     "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#develop",
-    "matrix-widget-api": "^0.1.0-beta.18",
+    "matrix-widget-api": "^1.0.0",
     "minimist": "^1.2.5",
     "opus-recorder": "^8.0.3",
     "pako": "^2.0.3",