feat: support Firebase Cloud Messaging

[robingenz]

Is your feature request related to a problem? Please describe:

Firebase Cloud Messaging is not currently supported.

Describe the solution you'd like:

Add a Firebase Cloud Messaging plugin.

Describe alternatives you've considered:

Additional context:

[HeikoKanzler]

+1

(and thank you for the great work!)

[mesqueeb]

+1 ! currently I can't get push notifications on Android because of this issue for the fcm plugin:
capacitor-community/fcm#99

so official support for FCM on capacitor-firebase would be really awesome!

[robingenz]

The first dev version is ready. 🎉 It would be great if someone could support me with testing.
I am happy about any feedback!

npm i @capacitor-firebase/messaging@0.2.1-dev.17f1a69.1651697626

Docs: https://github.com/robingenz/capacitor-firebase/blob/d4bafb5ce047499995ba9890597b9e98eff489e4/packages/messaging/README.md

[mesqueeb]

Does the plugin work completely standalone or do we also need @capacitor/push-notifications installed as peer dependency?

[robingenz]

Does the plugin work completely standalone or do we also need @capacitor/push-notifications installed as peer dependency?

completely standalone 👌

[robingenz]

To be more precise: You don't need the @capacitor/push-notifications plugin, but you can still use it in combination.