Don't require triggering Locate Current Document action twice
Clicking the toolbar button twice or triggering the context menu item twice or activating the shortcut twice is highly inconvenient for those who prefer to keep the auto-sync option off. Toggling auto-sync should be less frequent and thus doesn't require a shortcut, can be hidden in a tool button's popup menu. Two actions with the same function (syncActionMenu and syncSubAction) are necessary to allow both locating the current document and toggling auto-sync from the context menu when Projects Toolbar is hidden. Enable/disable all 3 actions in updateSyncAction(). Enabling/disabling only syncActionMenu does not prevent calls to ProjectManagerView::locateCurrentDocument() via existing and possible future shortcuts of the two sub-actions.