[website] Add ViaWallet explorer to site
Summary: Found another explorer for BCHA
Checked out the explorer to make sure it agrees with others, and local node
Built and ran the site locall to see that it looks good, and link works.
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D8995