Remove transaction dataclasses in client_models.py

[drknzz]

Feature Request

New transaction dataclasses have been added in #649, leaving us with 2 dataclasses for each transaction:

net/models/transaction.py
net/client_models.py

We should possibly remove the old transaction classes and replace their usages with the new ones.

[cptartur]

Blocked after 0.11.0. This should be a part of the general refactor I think.

[cptartur]

Transactions returned from gateway are different than the ones we send. They cannot be combined.