Diff View: Scroll to center of hunks when reviewing (#25846)

When reviewing hunks, scroll to put them at the center of the screen
so you can better see the context around that hunk.

The field `center_cursor` was added to the actions `editor::GoToHunk`
and `editor::GoToPrevHunk`, this was set to `false` by default in
keymaps, as it wouldn't help with in-editor navigation.

The field is set to `true` for when you trigger `git::StageAndNext`
and `git::UnstageAndNext`, this is also `true` for the buttons in the
Diff View toolbar.

Release Notes:

- N/A

crates/zed/src/zed/quick_action_bar.rs

@@ -182,8 +182,18 @@ impl Render for QuickActionBar {
                             .action("Next Problem", Box::new(GoToDiagnostic))
                             .action("Previous Problem", Box::new(GoToPrevDiagnostic))
                             .separator()
-                            .action("Next Hunk", Box::new(GoToHunk))
-                            .action("Previous Hunk", Box::new(GoToPrevHunk))
+                            .action(
+                                "Next Hunk",
+                                Box::new(GoToHunk {
+                                    center_cursor: true,
+                                }),
+                            )
+                            .action(
+                                "Previous Hunk",
+                                Box::new(GoToPrevHunk {
+                                    center_cursor: true,
+                                }),
+                            )
                             .separator()
                             .action("Move Line Up", Box::new(MoveLineUp))
                             .action("Move Line Down", Box::new(MoveLineDown))