Implement account domain verification

[mDuo13]

It would be handy to have a utility function that checks whether the Domain associated with an account object is is verified using an xrp-ledger.toml file. The actual code to do this is pretty straightforward. Here's an example script to do it: verify_domain.py.

I suggest adding this as a new method verify_domain(address:str, client:Client) in xrpl.account or something similar. Maybe it would be more efficient to have it take an AccountRoot object (such as returned by acount_info) to avoid the need for redundant lookups.

[JST5000]

There is a bounty that is closely related to this here: https://github.com/XRPLBounties/Proposals/blob/main/open_bounties/0062%20Account-based%20toml%20Lookup.md

The bounty is to add it to xrpl.org. This issue is slightly different in that it is asking to add the function to xrpl-py