The brand new Live Release or Work Pane

[nid90]

Redo how a release progresses in Tramline, both visually and logically.

This is a giant PR, that essentially rewrites the core functionality of Tramline:

• Remove the step/step-run/deployment/deployment-run abstraction completely
• Rally the release around a first-class idea of a Build
• Smaller, sub-components are now first-class, like WorkflowRun
• Wrap Production releases in a special (and first-class) way, ditto for Pre-Prod releases
• Redo how configuration works for a release. Configuration is now safe to edit at any point in time.
• Visually lay out the "live release" or the "work pane" in a vertical tab system with status information
• Each tab represents a meaningful "work area" and multiple tabs are grouped based on broad categories
• New changes are clearly and loudly notified to the user in different parts of the live release pane
• Builds can now be switched and selected during submissions (not always the latest)
• Release notes can be edited for multiple locales

There's a lot more to do here, but this is a releasable alpha cut that we can try with a few users.

Developer Notes

List of feature flags removed:

1. team_analysis_enabled
2. reldex_enabled
3. release_monitoring
4. allow_blocked_step
5. fixed_build_number
6. custom_release_version