Implement empty-workspace-above-first (#745)

* Implement empty-workspace-above-first option

* add two failing tests

* fix interactive_move_onto_empty_output_ewaf and
interactive_move_onto_first_empty_workspace tests

* Add two failing ewaf option toggle tests

* Fix adding/removing first empty workspace on option toggle

* Don't remove first empty workspace if focused

* Stop workspace switch when enabling ewaf

* layout/monitor: Offset workspace switch on adding workspace above

* Fix some initial active workspace ids with ewaf

* wiki: Document empty-workspace-above-first

---------

Co-authored-by: Ivan Molodetskikh <yalterz@gmail.com>

niri-config/src/lib.rs

@@ -444,6 +444,8 @@ pub struct Layout {
     pub center_focused_column: CenterFocusedColumn,
     #[knuffel(child)]
     pub always_center_single_column: bool,
+    #[knuffel(child)]
+    pub empty_workspace_above_first: bool,
     #[knuffel(child, unwrap(argument), default = Self::default().gaps)]
     pub gaps: FloatOrInt<0, 65535>,
     #[knuffel(child, default)]
@@ -460,6 +462,7 @@ impl Default for Layout {
             default_column_width: Default::default(),
             center_focused_column: Default::default(),
             always_center_single_column: false,
+            empty_workspace_above_first: false,
             gaps: FloatOrInt(16.),
             struts: Default::default(),
             preset_window_heights: Default::default(),
@@ -3310,6 +3313,7 @@ mod tests {
                     },
                     center_focused_column: CenterFocusedColumn::OnOverflow,
                     always_center_single_column: false,
+                    empty_workspace_above_first: false,
                 },
                 spawn_at_startup: vec![SpawnAtStartup {
                     command: vec!["alacritty".to_owned(), "-e".to_owned(), "fish".to_owned()],