Open pattern to specific bar from song editor

Nobody has claimed this yet.

This would apply to automation and instrument patterns.

It's currently convenient to use several short patterns in order to be able to quickly view the right part of a melody or automation. Doing this means the context of the surrounding bars is lost in the editor, and requires new patterns to be duplicated or created. In the automation editor, it's difficult to transition seamlessly from one pattern to the next, and duplicating automations often loses the value they were assigned to control.

Being able to quickly move to any bar of a pattern from the song editor would allow longer patterns to be used, which could improve workflow, especially in automation.

I see two potential ways to access this:
* Right click > "Go to bar" > Mouse over bar > Double click
* Mouse over bar > Modifier + Click

Highlighting which bar is selected would be useful here.

Mockup to clarify:

Start in the song editor and trace how it opens automation and instrument patterns. Compare the proposed Go to bar and modifier-click interactions, including highlighting the selected bar; done means a user can jump to any bar while preserving surrounding pattern context.

Written by the indexing model from the issue text.