55510e9cdf
In the future, we want to tightly control the state of the layout throught gestures, which requires hooking everything together with adjustments. This is the first step in this direction. Add a new custom layout manager for ControlsManager that allocates the search entry, the view selector, and the Dash, vertically. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1624>