[explorer] Remove "Address is empty" message.
Summary:
It's redundant, since it already displays a balance of 0 above
Also, the previous message is slightly confusing, as it could have tokens so not really empty
Also remove the divider in the case where there are no coins listed here.
Test Plan: Run it locally, check various addresses with and without coins and tokens
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D16309