Encoding tests encoding of a ssv message.

HasPartialQuorumButNoQuorum tests msg with unique f+1 signers.

HasQuorum tests msg with unique 2f+1 signers.

HasQuorum3f1 tests msg with unique 3f+1 signers.

NoPartialQuorum tests msg with < unique f+1 signers.

NoPartialQuorumDuplicate tests msg with < unique f+1 signers (but f+1 signers including duplicates).

NoQuorumDuplicate tests msg with < unique 2f+1 signers (but 2f+1 signers including duplicates).

PartialQuorumWithDuplicate tests msg with unique f+1 signers (but also including duplicates).

QuorumWithDuplicate tests msg with unique 2f+1 signers (but also including duplicates).