Reimplement the plugin to extend jenkinsci/gating-core-plugin

[olivergondza]

What feature do you want to see added?

Reimplement the guts of the plugin to leverage the gating-core-plugin, so multiple sources can be used at the same time.

Upstream changes

Example impl: https://github.com/jenkinsci/statuspage-gating-plugin

Are you interested in contributing this feature?

Interested: yes, available: no.