- Begin an implementation for FloatingTreeContainer
- Hide FloatingTreeContainer behind a feature flag
- Added the ability to apply filters on rendering
- Further refactoring of how Containers are handled in general
* refactor: select_window_from_point is now on WorkspaceContent
* refactor: moving more bits to WorkspaceContent, including advise_new_window
* refactor: various reworks, including toggle_floating
* refactor: renaming OutputContent to Output, WorkspaceContent to Workspace, + other refactors
* refactor: remove Workspace::get_tree and even fix a bug!
* backout: renderer.cpp changes