Adds the ability to navigate workspaces using the mouse
back/forward buttons when hovering over the sidebar. This
improves the user experience by providing a more intuitive
way to switch between workspaces.
This feature is only enabled when workspaces are enabled.
It intercepts the "AppCommand" events to handle back/forward
navigation.
This commit implements workspace switching using swipe gestures on the
navigator toolbox and tab bar. It introduces new event listeners for
`MozSwipeGesture*` events to detect and handle horizontal swipes.
The logic determines the swipe direction and switches to the next or
previous workspace accordingly, taking RTL layout into account. The
implementation uses a state object to track the gesture progress and
prevent unintended workspace switches.
