The isBtcAddress validator fails validation on the new taproot bitcoin address format (62 characters), as well as testnet addresses.

This PR adds support for the testnet prefixes listed in (this article) as well as the new taproot addresses (Bech32m) which are very similar to Bech32.

In addition, the characters 1 b i o were removed from the regex because they're not part of the Bech32 alphabet.

Let me know what you think !