* implement workspace back and forth
* Make our own ID counter instead of SerialCounter, use a newtype
* Rename FocusWorkspaceBackAndForth to FocusWorkspacePrevious
* Add focus-workspace-previous to tests
* Don't special case in switch_workspace_previous
* Minor clean up
* Add switch_workspace_auto_back_and_forth to tests
* Skip animation on switch_workspace_previous
* Preserve previous_workspace_id on workspace movement
* Make Workspace::id private with a getter
Reduce the chance it gets overwritten.
* Add test for workspace ID uniqueness
* Update previous workspace ID upon moving workspace across monitors
---------
Co-authored-by: Ivan Molodetskikh <yalterz@gmail.com>
FluxTape