Provide a UI to customize editor background actions

### Description

Provide a UI to allow customization and/or hiding of the editor background actions and logo.

### Use case/motivation

The editor background actions added in #7171 (based on #5591) are configured via the config file system. It is possible to change the actions, or hide them entirely, using the config file system. However, there is no user-facing UI to do so. A UI with action browser (possibly similar to the toolbar customizer) would be useful. It should also be possible for platform applications to disallow customization.

The default IDE configuration (and file structure) is shown at https://github.com/apache/netbeans/blob/master/nb/ide.branding/src/org/netbeans/modules/ide/branding/layer.xml#L41

Start by reading the default IDE configuration in nb/ide.branding/src/org/netbeans/modules/ide/branding/layer.xml and the editor background actions introduced in #7171, based on #5591. Done means users can customize or hide the editor background actions and logo through a UI, while platform applications can disallow customization.

Written by the indexing model from the issue text.