Add and configure items for v2

[Gus Reiber]

https://youtu.be/LEKMMZYg9B4

https://issues.jenkins-ci.org/browse/JENKINS-31162

Hey all,

Attached is the latest screen video showing a possible item creation and configuration UX flow for Jenkins in v2.

A series of PRs is on the way:

1. https://github.com/jenkinsci/jenkins/pull/2006 (merged)
   
2. https://github.com/jenkinsci/jenkins/pull/2046 (in review)
   
3. https://github.com/jenkinsci/jenkins/pull/2080 (work-in-progress)
   

If you are interested, please jump into the discussion.

[Gus Reiber]

Hey all, if you are at all interested in the Jenkins GUI for v2 I have a PR you might look at:https://github.com/jenkinsci/jenkins/pull/2106

At the moment, it is closed while I fix some tests, but open for comments.