asim: add randomness to cluster setup

The issue tracks work for adding randomness to initial cluster setup.

Related: https://github.com/cockroachdb/cockroach/issues/106192

In this second phase, the aim is to amplify the randomness into the initial
cluster generation. Specifically, we will introduce more randomness to zone
configuration, initial node placements, node localities, and node attributes.
This task presents challenges due to potential dependencies between zone
configuration and node localities. In addition, this task also requires
comprehensive validation to ensure the generated cluster setup is somewhat
functional and valid.

Furthermore, we plan to support randomized node status change and randomized
node membership (active, decommissioning or decommissioned members for gossip
protocol).

Upon completion, the goal is to scale up these tests to enable more extensive
exploratory testing to uncover more interesting edge cases. To handle this
larger system, we will likely need to shift from the current go-test approach to
a testing framework similar to roachtest.

Jira issue: CRDB-29506