Avoid unnecessary DB writes (#29417)

Part of https://github.com/zed-industries/zed/issues/16472

* Adds debug logging to everywhere near INSERT/UPDATEs in the DB

So something like 
`env RUST_LOG=debug,wasmtime_cranelift=off,cranelift_codegen=off,vte=off
cargo run` could be used to view these (current zlog seems to process
the exclusions odd, so not sure this is the optimal RUST_LOG line) can
be used to debug any further writes.

* Removes excessive window stack serialization

Previously, it serialized unconditionally every 100ms.
Now, only if the stack had changed, which is now check every 500ms.

* Removes excessive terminal serialization

Previously, it serialized its `cwd` on every `ItemEvent::UpdateTab`
which was caused by e.g. any character output.
Now, only if the `cwd` has changed at the next event processing time.

Release Notes:

- Fixed more excessive DB writes

crates/vim/src/state.rs

@@ -1644,6 +1644,7 @@ impl VimDb {
         path: Arc<Path>,
         marks: HashMap<String, Vec<Point>>,
     ) -> Result<()> {
+        log::debug!("Setting path {path:?} for {} marks", marks.len());
         let result = self
             .write(move |conn| {
                 let mut query = conn.exec_bound(sql!(
@@ -1694,6 +1695,7 @@ impl VimDb {
         mark_name: String,
         path: Arc<Path>,
     ) -> Result<()> {
+        log::debug!("Setting global mark path {path:?} for {mark_name}");
         self.write(move |conn| {
             conn.exec_bound(sql!(
                 INSERT OR REPLACE INTO vim_global_marks_paths