Remove hard coded Gas Limit to allow arbitrary contract code registration.

[jfarid27]

Description

Currently, you cannot use arbitrary contract code to call on a registration for a darknode because of the hard coded gas limit found here:

command-center/src/lib/ethereum/contractWrites.ts

Line 123 in 9c0423c

const hardCodedGas = 500000;

Steps to Reproduce

1. Try to approve an Aragon Agent to register a darknode. Console will error with gas required exceeds allowance (10000000) or always failing transaction.

Possible Fixes

• Remove the hard coded gas limit. I believe this should fix things.