Annotations: Allow filtering out releases by is_draft and is_prerelease so I can display actual releases only

[michaelniemand]

Right now, when defining an annotation in a dashboard with the GH plugin installed, releases can not be filtered by their type.

Thus, the bar superimposed on a graph always shows all releases including drafts and prereleases. Often this is not desirable because drafts and prereleases rarely go on a prod environment for example.

Therefor, requesting an option to filter releases by their type. This would allow displaying the bar for a new release only on graphs for which they are relevant.