Sync-lock not honored when Timeshifting labels

[petersampsonaudacity]

Describe the bug
Sync-lock is not honored when Timeshifting labels.

If you have sync-locked audio clip and associated label:
a) when you timeshift the selected label (either from the Clip-handle drag-bar affordance or by using the Time Shift tool) then the label moves on sync with the clip.
b) BUT if you select the label and timshift it (either with the new label drag-bar or by using Time Shift Tool) the only the label moves - and thus the sync-lock is ignored

This was originally logged as Bugzilla 2813 (which is now closed in favor of this GitHub Issue)
https://bugzilla.audacityteam.org/show_bug.cgi?id=2813
Bug 2813 - Sync-lock not honored when Timeshifting labels

To Reproduce
Steps to reproduce the behavior:

1. create a project with 3 labeled audio clips (see screenshot below)
2. Turn on sync-lock
3. select just the second audio clip
4. Observe: synced clock icons in the associated label
5. with the Clip-handle drag-bar affordance (or the Time Shift Tool) move the audio clip left or right
6. Observe: the label moves in sync with the audio - expected behavior
7. select just the second label range in the label track
8. Observe: synced clock icons in the associated audio
9. with the label drag-bar or the Time Shift Tool move the label left or right
10. Observe: the label moves but the audio does not move in sync - incorrect behavior, sync-lock ignored

Expected behavior
Sync-lock to be honored regardless of the selection

Screenshots

Additional information (please complete the following information):

• OS: Windows 10 - but assume all OS
• Version Audacity 3.1.0

Additional context
With the focus on drag-bars for 3.1.0 I think it's fairly important to fix this for 3.1.0 release. Hence I logged this here as P2 upping it from the previous P3 it had on Bugzilla.

The original bug was logged pr drag-bars so the Steps then only focused on Tome Shift tool

[AnitaBats]

During the backlog grooming, we've decided to out this into the backlog for some time. We need to think more about the sync-lock redesign

[petersampsonaudacity]

During the backlog grooming, we've decided to out this into the backlog for some time. We need to think more about the sync-lock redesign

Sync-lock has many rough edges - not least the way an SLTG is defined ;-)

[petersampsonaudacity]

See also #1436 Sync lock can move touching labels

[LWinterberg]

this won't get fixed and instead be replaced with grouping