[flutter_webrtc] Update libwebrtc to m114 version

[wanchao-xu]

1. Update libwebrtc with m114 version of webrtc sdk(https://github.com/webrtc-sdk/webrtc) for tizen platform.
2. Update flutter webrtc to 0.9.46 version.
3. Update and format flutter_webrtc_demo.
4. Support empty candidate for 'addCandidate' api([flutter_webrtc] Crash when trying to add empty IceCandidate #623).

[Vasques1995]

My understanding right now is that the empty IceCandidate is just being ignored, although this would prevent the underlying crash it would also prevent the connection between peers. The empty candidate is part of the webrtc, the libwertc being used should be able to receive and deal with it.

[wanchao-xu]

My understanding right now is that the empty IceCandidate is just being ignored, although this would prevent the underlying crash it would also prevent the connection between peers. The empty candidate is part of the webrtc, the libwertc being used should be able to receive and deal with it.

I have updated libwebrtc with m114 version of webrtc sdk(https://github.com/webrtc-sdk/webrtc) on Tizen platform (#625).
I also use flutter_webrtc_demo to test the empty IceCandidate with debug libwebrtc. There is an error if candidate is empty

01-01 09:06:56.653+0900 I/ConsoleMessage(P10798, T10845): flutter: Received data: {"type":"candidate","data":{"to":"606143","from":"842756","candidate":{"sdpMLineIndex":0,"sdpMid":"0","candidate":""},"session_id":"842756-606143"}}
01-01 09:06:56.653+0900 I/TizenWebRTC(P10798, T10884): (webrtc_sdp.cc:424): Failed to parse: "". Reason: Expect line: candidate:<candidate-str>

webrtc sdk can't parse empty candidate.

[JSUYA]

Hi
There is an analyze error below related to WillPopScope.
I think it would be a good to also contain fix.
related pr : #627

2023-11-16T06:50:34.1608399Z Running command: "dart analyze --fatal-infos" in /home/runner/work/plugins/plugins/packages/flutter_webrtc
2023-11-16T06:50:34.2456104Z Analyzing flutter_webrtc...
2023-11-16T06:50:37.1069766Z 
2023-11-16T06:50:37.1118442Z    info - example/flutter_webrtc_demo/lib/src/call_sample/call_sample.dart:287:12 - 'WillPopScope' is deprecated and shouldn't be used. Use PopScope instead. This feature was deprecated after v3.12.0-1.0.pre. Try replacing the use of the deprecated member with the replacement. - deprecated_member_use
2023-11-16T06:50:37.1123290Z    info - example/flutter_webrtc_demo/lib/src/call_sample/call_sample.dart:287:12 - 'WillPopScope.new' is deprecated and shouldn't be used. Use PopScope instead. This feature was deprecated after v3.12.0-1.0.pre. Try replacing the use of the deprecated member with the replacement. - deprecated_member_use

[wanchao-xu]

@JSUYA , I have removed the deprecated widget 'WillPopScope'. Please refer to 7480351

[wanchao-xu]

@swift-kim, please review this update of webrtc.