Ability to select multiple tracks and clone, remove and clear them all at once

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### Enhancement Summary
Selecting multiple tracks and then applying actions to clear, remove or clone them all at once.

#### Justification
I don't know how this happened, but after opening my project after some days, so many Automation Tracks are created:

In such situations, if I can delete them all by selecting them either by `CTRL`+`Left Click` individually or `SHIFT`+`Left Click` the last track with contiguous tracks to be deleted. Although, along with the option to delete, cloning and clearing them at once also can be added as options, as the code for them would be of same kind (I think so).

#### Mockup
Selecting tracks by either `CTRL`+`Left Click` for non-contiguous tracks or `SHIFT`+`Left Click` for contiguous tracks should look something like this, and when clicking the  icon, the menu should contain **Clone selected tracks**, **Remove selected tracks** and **Clear selected tracks** instead of **Clone this track**, **Remove this track** and **Clear this track** options respectively, like this:
Also, the other options, like **Change clip color** or **Clear clip colors** should apply to all of the selected tracks.

The issue names no files or tests; start by locating the automation-track selection and track action-menu entry points in the desktop UI. Verify how clone, remove, clear, and clip-color actions currently target one track, then check contiguous and non-contiguous multi-selection behavior for each bulk action.

Written by the indexing model from the issue text.