[FEATURE] Optional by adding few onPressedCallback in AgoraVideoButtons Widget class

[gtiger165]

Is your feature request related to a problem? Please describe.
This lib ui kit really helpful for me to implement Video Call in flash, but some cases like when i pressed end call button i need to show some pop up dialog first, then after i choose an option execute end button call functionality.

Describe the solution you'd like
So i've read the code in buttons.dart. I believe in AgoraVideoButtons there's a param like disconnectButtonChild, if i want to customize ui button for each functionallity that i need. So the solution that i propose is by adding onPressedCallback params like "onDisconnectButtonPressed" and etc.

Describe alternatives you've considered
as example, in method _disconnectCallButton :

...
  AgoraVideoButtons(
      client: controller.videoClient,
      // onDisconnectButtonPressed return Future<void>
      onDisconnectButtonPressed: () async {}
  ),
...
Widget _disconnectCallButton() {
    return widget.disconnectButtonChild != null
        ? RawMaterialButton(
            onPressed: () async {
              // before executing _onCallEnd method
              // implement onDisconnectButtonPressed Function first
              await onDisconnectButtonPressed();
              await  _onCallEnd(context);
            },
            child: widget.disconnectButtonChild,
          )
        : RawMaterialButton(
            onPressed: () => _onCallEnd(context),
            child: Icon(Icons.call_end, color: Colors.white, size: 35),
            shape: CircleBorder(),
            elevation: 2.0,
            fillColor: Colors.redAccent,
            padding: const EdgeInsets.all(15.0),
          );
  }

Additional context
So in my case i only need onPressedCallback on disconnectButtonChild, thank you for your attention and i apologize if there something wrong in my explanation. I'll be looking foward for next feature of this library.

[Meherdeep]

@gtiger165 Thanks for submitting your suggestion and yes, I agree that will be a helpful feature. You can submit a PR for the same or I will make sure to add this feature in our next release.

[gtiger165]

thanks @Meherdeep, i'll try to submit later on my free time.

[Meherdeep]

@gtiger165 This feature has been added to the latest release v1.0.3