Allow buffer search in project search (#23819)

Closes #13437
Closes #19993

Release Notes:

- Allow searching within the results of a project search
- vim: Fix `/`/`?`, `n`/`N`, `gn`/`gN`,`*`/`#` in project search results

---------

Co-authored-by: Nico <nico.lehmann@gmail.com>

crates/editor/src/editor.rs

@@ -728,6 +728,7 @@ pub struct Editor {
     expect_bounds_change: Option<Bounds<Pixels>>,
     tasks: BTreeMap<(BufferId, BufferRow), RunnableTasks>,
     tasks_update_task: Option<Task<()>>,
+    in_project_search: bool,
     previous_search_ranges: Option<Arc<[Range<Anchor>]>>,
     breadcrumb_header: Option<String>,
     focused_block: Option<FocusedBlock>,
@@ -1426,6 +1427,7 @@ impl Editor {
             ],
             tasks_update_task: None,
             linked_edit_ranges: Default::default(),
+            in_project_search: false,
             previous_search_ranges: None,
             breadcrumb_header: None,
             focused_block: None,
@@ -1703,6 +1705,10 @@ impl Editor {
         self.collaboration_hub = Some(hub);
     }
 
+    pub fn set_in_project_search(&mut self, in_project_search: bool) {
+        self.in_project_search = in_project_search;
+    }
+
     pub fn set_custom_context_menu(
         &mut self,
         f: impl 'static