Remove stuck tooltips (#22548)

Closes https://github.com/zed-industries/zed/issues/21657

Follow-up of https://github.com/zed-industries/zed/pull/22488
Previous PR broke git blame tooltips, which are expected to be open when
hovered, even if the mouse cursor is moved away from the actual blame
entry that caused the tooltip to appear.

Current version moves the invalidation logic into `prepaint_tooltip`,
where the new data about the tooltip origin is used to ensure we
invalidate only tooltips that have no mouse cursor in either origin
bounds or tooltip bounds (if it's hoverable).


Release Notes:

- Fixed tooltips getting stuck

crates/gpui/src/window.rs

@@ -1557,6 +1557,19 @@ impl<'a> WindowContext<'a> {
         let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
 
         let mut tooltip_bounds = Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
+        // Element's parent can get hidden (e.g. via the `visible_on_hover` method),
+        // and element's `paint` won't be called (ergo, mouse listeners also won't be active) to detect that the tooltip has to be removed.
+        // Ensure it's not stuck around in such cases.
+        let invalidate_tooltip = !tooltip_request
+            .tooltip
+            .origin_bounds
+            .contains(&self.mouse_position())
+            && (!tooltip_request.tooltip.hoverable
+                || !tooltip_bounds.contains(&self.mouse_position()));
+        if invalidate_tooltip {
+            return None;
+        }
+
         let window_bounds = Bounds {
             origin: Point::default(),
             size: self.viewport_size(),