Performance benchmarking

[sidharthv96]

We need to add performance benchmarks to PRs.
Does anyone have suggestions for tools which we can use?

#4697 removed parsing a diagram multiple times, but we don't know the overall impact it made on rendering. Maybe it's 10x faster, perhaps it's 1.1x faster, who knows ?!

[Yokozuna59]

Vitest support it: https://vitest.dev/guide/features.html#benchmarking-experimental, which uses tinybench under the hood.