Tracing: trace render times as render-path (#89763)
Analagous to the existing compile-path, which records compile times for
each path in development, we now record path render times as
`render-path`. It corresponds with the value we write to the tty when
rendering routes (e.g. `GET / 200 in 228ms (compile: 129ms, render:
99ms)`).
This change also adds tests for recording hmr data in the trace file.
Test Plan:
- CI
- Made changes in a test app and verified the trace file included valid
entries for these. Confirmed the duration matched what was shown in
the cli.
