Add high level component overview back to architecture page

What does this MR do?

As discussed in Stan's Office Hours, this MR is to add the high level component diagram back onto the architecture page. The mermaid diagram is excellent, but there is value in keeping both. The other diagram is useful for people wanting a high level overview.

Does this MR meet the acceptance criteria?

Conformity

• Documentation created/updated or follow-up review issue created