use project templates

This change takes advantage of the project templating system recently
implemented in Zuul.

Some -jslint jobs are added as a result, they are harmfull since they
are non voting.

Some extensions now have a test pipeline since they are triggering
tests: Geodata, LabeledSectionTransclusion, EtherEditor, TitleBlacklist,
ParserFunctions, WikiLove).

WikimediaIncubator now has the gate-and-submit.

Validator had the check-only pipeline (which votes V+2) despite having
unit tests. It is now using the check pipeline (which votes V+1).

Change-Id: I8fdcd2bff447e22b87c1ea31e09a8c95d0397714