Update architecture diagram

[sveitser]

Closes #1439 Closes #1462

To hopefully make it easier to understand and maintain the diagram has been split into an architecture and sequence diagram.

This PR:

Tries to make a reasonable diagram for the overall architecture.

This PR does not:

The diagram doesn't aim to be 100% accurate (I think that's no feasible) but give enough of a mental aid for developers and others to understand which components talk to each other.

[philippecamacho]

These diagrams are really useful! I wonder if it would be worth extending or adding a new sequence diagram for optimistic rollups to describe what happens when some rollup node challenges the state with a fraud proof.

[sveitser]

Should we add the interaction numbers as comments on the architecture diagram as well, so it is a little easier to match it up with the sequence diagram?

7dbf70e106b187dc3bc7666d0cc249175577f1f9

[sveitser]

These diagrams are really useful! I wonder if it would be worth extending or adding a new sequence diagram for optimistic rollups to describe what happens when some rollup node challenges the state with a fraud proof.

Yeah should add that. I will try to get around to it.

[sveitser]

@philippecamacho please take another look

[sveitser]

@imabdulbasit yes that was ugly, fixed it