Avoid creating occlusions for editor blocks, since these block mouse wheel events (#20649)

Just block mouse down events, and in the case of the inline assist
prompt, set the default cursor.

Release Notes:

- N/A

Co-authored-by: Richard <richard@zed.dev>

crates/editor/src/editor.rs

@@ -10431,7 +10431,7 @@ impl Editor {
                                         text_style = text_style.highlight(highlight_style);
                                     }
                                     div()
-                                        .occlude()
+                                        .block_mouse_down()
                                         .pl(cx.anchor_x)
                                         .child(EditorElement::new(
                                             &rename_editor,
@@ -14681,7 +14681,7 @@ pub fn diagnostic_block_renderer(
             .group(group_id.clone())
             .relative()
             .size_full()
-            .occlude()
+            .block_mouse_down()
             .pl(cx.gutter_dimensions.width)
             .w(cx.max_width - cx.gutter_dimensions.full_width())
             .child(

crates/editor/src/hunk_diff.rs

@@ -435,7 +435,7 @@ impl Editor {
 
                     h_flex()
                         .id(cx.block_id)
-                        .occlude()
+                        .block_mouse_down()
                         .h(cx.line_height())
                         .w_full()
                         .border_t_1()
@@ -714,7 +714,7 @@ impl Editor {
 
                 h_flex()
                     .id(cx.block_id)
-                    .occlude()
+                    .block_mouse_down()
                     .bg(deleted_hunk_color)
                     .h(height as f32 * cx.line_height())
                     .w_full()