Rework edit prediction preview mode (#24700)

Don't animate the cursor when previewing jumps.
Instead, display the jump popover with a line that resembles a cursor,
indicating the jump destination. If the jump destination is outside of
the view port, there is an extra step in which `tab` scrolls the
viewport to reveal the jump destination.

Release Notes:

- N/A

---------

Co-authored-by: danilo-leal <daniloleal09@gmail.com>
Co-authored-by: agu-z <hi@aguz.me>

crates/editor/src/scroll.rs

@@ -3,6 +3,7 @@ pub(crate) mod autoscroll;
 pub(crate) mod scroll_amount;
 
 use crate::editor_settings::{ScrollBeyondLastLine, ScrollbarAxes};
+use crate::EditPredictionPreview;
 use crate::{
     display_map::{DisplaySnapshot, ToDisplayPoint},
     hover_popover::hide_hover,
@@ -495,6 +496,15 @@ impl Editor {
         hide_hover(self, cx);
         let workspace_id = self.workspace.as_ref().and_then(|workspace| workspace.1);
 
+        if let EditPredictionPreview::Active {
+            previous_scroll_position,
+        } = &mut self.edit_prediction_preview
+        {
+            if !autoscroll {
+                previous_scroll_position.take();
+            }
+        }
+
         self.scroll_manager.set_scroll_position(
             scroll_position,
             &display_map,