Support non-validator nodes in e2e tests

[goran-ethernal]

Description

This PR supports non-validator nodes in e2e tests.
It only gives the manifest and genesis files those validators that have a ValidatorPrefix from the TestClusterConfig.
Non-validator nodes have a prefix test-non-validator-, which is fixed in tests to separate them from the validator nodes.

This PR also does two things:

• Merges TestE2E_Consensus_Basic_WithNonValidators and TestE2E_Consensus_Sync_WithNonValidators.
• Removes --validator-set-size flag from genesis command, since it was not used.

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

[Stefan-Ethernal]

Nice one 🔥