Update UDC helpers to use the new UDC contract

[HACKER097]

Fixes: #772

Here are the changes I have made:

1. Updated udcAddressCairoV2 to the new address
2. Added NewUDCOptions() which makes UDCCairoV2 the default value
3. Update tests to expect the new default value

Note: The TestPrecomputeAddressForUDC tests still fail, because they rely on hardcoded values from real transactions, which I assume use the old address, so their values will have to be changed too.

Please let me know if this is the expected way of updating the address and setting the default value. The NewUDCOptions functions does feel a bit unnecessary for this tiny change, but also less hackey.

[thiagodeev]

Hey @HACKER097! Thanks!
I'll take a look soon. Sorry, I'm focused on rpcv0.10.0