zlog: Use zlog as default log implementation (#28612)

Still TODO:

- [x] Remove old log implementations
- [x] More cleanup
- [x] Verify atomic/lock logic
- [x] More tests
- [ ] ??? Ansi coloring when logging to stdout

Release Notes:

- N/A

Cargo.lock

@@ -18206,7 +18206,6 @@ dependencies = [
  "settings",
  "settings_ui",
  "shellexpand 2.1.2",
- "simplelog",
  "smol",
  "snippet_provider",
  "snippets_ui",
@@ -18555,7 +18554,9 @@ name = "zlog"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "chrono",
  "log",
+ "tempfile",
  "workspace-hack",
 ]