[suggestion] Make `Action` and `Filter` non-generic

[DCNick3]

Action and Filter are currently generic over a type of filter they use. This is used in iroha_core to split event triggers for events coming from different sources.

This is iroha_core an implementation detail that makes iroha_data_model harder to understand for the user.

Action should have a concrete event filter type specified and iroha_core should have its own types for the specialized event filters which would not be exposed to the user.