Rename contract names from fee to l2

[ddoktorski]

Investigate how to verify that there is enough STRK tokens on an account to be deployed using DeployAccountV3.

Discussed here

[ddoktorski]

Both L1_GAS and L2_GAS in the resource_bounds are specified in FRI, hence we can simply call STRK contract to check a balance. We need to decide whether we should perform this check on the starknet.py side at all, since RPC will throw an error if balance is not sufficient anyway. The current error doesn't include token name, it only provides the information Account balance is smaller than the transaction's max_fee..