Key refresh w/o aux data (re)gen

[survived]

We want to be able to run key refresh protocol w/o aux data (re)gen. There are two approaches to do so:

1. Delete aux (re)gen part from existing key refresh implementation
   If one needs to crry out key refresh & aux data (re)gen simultaneously, they would need to run two protocol separately (can be done in parallel). In other cases, when user needs to run either of the protocols, they just run it directly.
2. Add a bunch of conditions, so key refresh is configurable (whether we want to carry out exact part of the protocol, etc.)

We need to pick whatever approach that produces clearer and simpler code, with the fewest code duplication