Timelines and tracks

Description

Some helpers were added for Timelines, Tracks and Track Clips.
The Breakdown2 scan scene hooks now only considers the current timeline if scan_current_timeline_only is set to true in the Breakdown2 app settings.

For example:

premiere.tk-multi-breakdown2:
  <<: *breakdown2
  help_url: "https://developer.shotgridsoftware.com/tk-multi-breakdown2/index.html"
  hook_scene_operations: "{engine}/tk-multi-breakdown2/basic/scene_operation.py"
  hook_get_published_files: "{config}/tk-multi-breakdown2/studio/get_published_files.py"
  scan_current_timeline_only: true

What's Changed

• 11528 breakdown app2 by @gplsteph in #4

Full Changelog: v1.2.0...v1.2.1