op-node: Events diagrams generation

[protolambda]

Description

This implements:

• a struct-collecting event.Tracer, to gather data for diagram generation
• a sequence-diagram generating tracer (based on mermaid js)
• a timing-diagram generating tracer (custom SVG generation)

The outputs are .html files, with SVG content, ready to open in the browser.

PR depends on #11097

Example usage, in an action test:

	// add logging
	sequencer.eventSys.AddTracer(event.NewLogTracer(log, slog.LevelInfo))

	// add tracer, write at end of test
	seqTr := event.NewTimingTracer()
	sequencer.eventSys.AddTracer(seqTr)
	defer func() {
		require.NoError(t, os.WriteFile("custom_trace.html", []byte(seqTr.Output()), 0755))
		t.Log("written trace file")
	}()

Below diagrams visualize execution of TestEIP4844DataAvailability (action test)

Sequence diagram output example (incomplete screenshot, long scrolling page):

Timing diagram output example:

Tests

No tests, these are just nice-to-have debug tools.

Metadata

Fix #11098

[tynes]

This is sick

[ajsutton]

Very cool.

Fun fact: the Chrome dev tools Performance tab lets you import timing profiles in a JSON format and you can then view the timeline similar to the SVG but with filtering, zoom etc. I was used it to capture build timing info I think and it was really awesome but sadly I can't find info on the file format it uses now.