Address Tab: Allor Ctrl-F (filter) of tab to use bitcoincash: address
Address Tab: Allor Ctrl-F (filter) of tab to use bitcoincash: address

Basically the filter function just ignores the bitcoincash: prefix when
applying the filter.  This is so user can copy-paste addresses from
external/internal sources and not care if they have bitcoincash: prefix
attached.

Closes #1440

fyookball/electrum,fyookball/electrum,fyookball/electrum