Actions used in the GUI frontend.
Every Action is a descendant of {@link workbench.gui.actions.WbAction} that provides
several utility functions to work with Actions.
Each WbAction will register itself with the {@link workbench.resource.ShortcutManager}, in order
to allow a remapping of keyboard shortcuts.
Some actions are not created during startup, in this case they have to be
registered with the Shortcut manager using the ActionRegistration class.
If that is not done, they won't be available in the "Configure shortcuts" dialog
which is implemented through {@link workbench.gui.settings.ShortcutEditor}