Delete + Automation button to delete all automation in a clip

[git-moss]

Requires function to delete automation. https://github.com/teotigraphix/Framework4Bitwig/issues/262

Note: Since Bitwig 5.1 there are now the actions: delete_all_project_automation:Project:Delete All Project Automation delete_all_automation_owned_by_selection:Project:Delete All Automation Owned by Selection

First one needs to have the track selected and it needs to be focused. Second one requires a dialog confirmation.