debugger: Remember pane layout from previous debugger session (#28692)

This PR makes a debugger's pane layout persistent across session's that
use the same debug adapter.

Release Notes:

- N/A

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>
Co-authored-by: Cole Miller <m@cole-miller.net>

crates/debugger_ui/src/session/running/breakpoint_list.rs

@@ -27,7 +27,7 @@ use ui::{
 use util::{ResultExt, maybe};
 use workspace::Workspace;
 
-pub(super) struct BreakpointList {
+pub(crate) struct BreakpointList {
     workspace: WeakEntity<Workspace>,
     breakpoint_store: Entity<BreakpointStore>,
     worktree_store: Entity<WorktreeStore>,