calculatenetworkfee MUST calculate complete proper network fee, if we have
some extensions enabled and some attributes should be paid for that they're a
part of the equation too.
Unfortunately Go doesn't allow to easily reuse readers in full packages, still
we can have this wrapper with a little overhead (the alternative is to move
specific methods into types of their own, but I'm not sure how it's going to
be accepted user-side).
Notice that int64 types are used for gas per block or registration price
because the price has to fit into the system fee limitation and gas per block
value can't be more than 10 GAS. We use int64 for votes as well in other types
since NEO is limited to 100M.
And test it with the RPC server.
Notice that getters still return int64 instead of *big.Int, that's because
these values are very limited and technically could even fit into an int (but
that seems to be too dangerous to use for long-term compatibility).
They were first introduced in a058598ecc and
then carefully moved in 648e0bb242, but it looks
like they were never used by any external code. This code can be useful on the
server, but the server has its own params package to deal with
parameters. Clients usually create Parameters and then get results as
stackitem.Items, so they don't use this code either. So there is zero point in
keeping it.
