fix deletion of effect chain presets created in current session

[ronso0]

• initialize readOnly correctly (false) for chain presets just created via the preset menu, regression from Effects: allow clearing chains with empty '---' preset #10859
• add "Rename preset" action to preset menu

• fix occasional issue in Preferences -> Effects:
  clicking any of the preset action buttons (Rename, Delete, ..) does sometimes clear the selection in the list views above, i.e. the buttons won't do anything.
  Looks like the events are processed in unpredictable order: sometimes the Delete button gets focus and the list focus as well as the selection is cleared, sometimes the selection is cleared after the Delete dialog is closed (aborted, so the selected item is still in the list and selection should not change

[ronso0]

This can be merged as is, though I need to figure what's wrong with the focus behaviour / event processing in that dialog.

Can anyone else reproduce this (I'm using Qt 5.12.8 on Ubuntu 20.04):

• open Pref -> Effects
• select one chain preset in the Quick Effect Chain Presets list
• click Delete
• list selection is cleared, Delete button does nothing

[ronso0]

Done, ready for review.

clicking any of the preset action buttons (Rename, Delete, ..) does sometimes clear the selection in the list views above, i.e. the buttons won't do anything.
Looks like the events are processed in unpredictable order: sometimes the Delete button gets focus and the list focus as well as the selection is cleared, sometimes the selection is cleared after the Delete dialog is closed (aborted, so the selected item is still in the list and selection should not change

I changed the eventFilter return value to QWidget::eventFilter and can't reproduce the issue anymore.
Furthermore, the lists are now reloaded only when the state actually changed, i.e. when presets are renamed, deleted or imported.

[Swiftb0y]

why ||?

[ronso0]

This should clear the info labels and return if (selIndices.count() != 1).

I pushed the simplified version. Thanks!

[Holzhaus]

There are merge conflicts now.

[ronso0]

Conflicts resolved.

In case the new tr string is an issue I can remove 46f2f91 and open a separate PR against main.

[ronso0]

pa-ping..

[daschuer]

LGTM and still works! Thank you.