Test with Mocha and Mainnet genesis files

[rootulp]

Context

#3843 (comment)

Problem

We currently have no test that starts a node using the Mocha (or Mainnet) genesis file. This means that if we introduce a regression (like #3840) we won't get signal that a consensus node can't start and block sync.

Proposal

Implement a test that starts a node using the Mocha genesis file and waits until the first block is processed. Repeat for Mainnet Beta genesis file.