Align Analytics Agent naming with other foundational agents

Other foundational agents have been recently renamed to the following:

And in the docs, we're referring to "the Security Analyst Agent" and "the Planner Agent."

That makes our "Analytics Agent" naming a bit misaligned with the rest.

@sselhorn proposed we call it Data Analyst (Agent), similarly to the Security Analyst (Agent).

If we are happy with the proposal let's rename, or let's find an alternative names that works