Add action to go to next/previous git diff in editor

Co-Authored-By: Kay Simmons <kay@zed.dev>

crates/editor/src/selections_collection.rs

@@ -594,7 +594,6 @@ impl<'a> MutableSelectionsCollection<'a> {
         self.select_anchors(selections)
     }
 
-    #[cfg(any(test, feature = "test-support"))]
     pub fn select_display_ranges<T>(&mut self, ranges: T)
     where
         T: IntoIterator<Item = Range<DisplayPoint>>,