debugger: Touchups to log breakpoints (#27675)

This is a slight refactor that flattens Breakpoint struct in
anticipation of condition/hit breakpoints. It also adds a slight delay
before breakpoints are shown on gutter hover to make breakpoints less
attention grabbing.
Release Notes:

- N/A

crates/workspace/src/persistence/model.rs

@@ -10,7 +10,7 @@ use db::sqlez::{
 };
 use gpui::{AsyncWindowContext, Entity, WeakEntity};
 use itertools::Itertools as _;
-use project::{debugger::breakpoint_store::SerializedBreakpoint, Project};
+use project::{debugger::breakpoint_store::SourceBreakpoint, Project};
 use remote::ssh_session::SshProjectId;
 use serde::{Deserialize, Serialize};
 use std::{
@@ -264,7 +264,7 @@ pub(crate) struct SerializedWorkspace {
     pub(crate) display: Option<Uuid>,
     pub(crate) docks: DockStructure,
     pub(crate) session_id: Option<String>,
-    pub(crate) breakpoints: BTreeMap<Arc<Path>, Vec<SerializedBreakpoint>>,
+    pub(crate) breakpoints: BTreeMap<Arc<Path>, Vec<SourceBreakpoint>>,
     pub(crate) window_id: Option<u64>,
 }