Added Github App Credentials support

[trispad]

@jon-schuck-MA added support for Github App Credentials from the github-branch-source plugin. The github-branch-source plugin is optional and the credentials will only will be created when the plugin is installed.

I am attempting to take their work from #87 to done.

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[julio-je-yaguez]

it would be awesome to get this one merged, is there anything that's missing? I can try to help if so

[trispad]

Looks like there are some conflicts now due to changes from v1.2.0. Once this is integrated and tested we need 👀 from the maintainers.

[Larusso]

Hey I would also add my help here to get this one merged and released :)

[denis-matchenko]

Hello, do you have ETA?

[tomcart90]

@trispad, we could really do with making us of those one, let me know if there's anything I can do to help get this over the line, it looks like it's nearly there!

[trispad]

@tomcart90 - What would be helpful is re-integrating this with the mainline. There were some changes made to main that need to be addressed in this PR. If you could do it I would be appreciative.

[asaf-the-ancient]

Guys, any progress with that?

[nickhuang016]

hello team, also would like to know, any updates?

[jkerrigan-chwy]

@trispad is this not merged because there are still errors?
@chriskilding has this been reviewed by you or fellow owners?