Remove ssv_types dependency on qbft

[Zacholme7]

Proposed Changes

ssv_types was importing the qbft crate which prevented us from using those types in qbft as it created a cyclic dependency. Types should ideally not depend on any other internal crates to prevent this from happening, so I moved the Data trait into types to keep it contained.

[dknopik]

I understand the reasoning behind this change and am fine with it. Just wanted to note my reasoning here: I was hoping that qbft could stay rather independent, i.e. usable for QBFT consensus without being specific to SSV (which it now is though the dependency on ssv_types).

[Zacholme7]

@dknopik okay yea that makes sense. Ill probably work on getting it 100% functional with the ssv type dependency which maps well to the spec and then once we have it working we can look at making it generic.