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/command_palette/Cargo.toml

@@ -20,6 +20,7 @@ command_palette_hooks.workspace = true
 db.workspace = true
 fuzzy.workspace = true
 gpui.workspace = true
+log.workspace = true
 picker.workspace = true
 postage.workspace = true
 serde.workspace = true