Support BTC Taproot address to build and sign RGB++ TX for examples

[duanyytop]

Now the RGB++ examples only support BTC P2WPKH address to build and sign RGB++ TX and the JoyID wallet and rgbpp-sdk/btc all support BTC P2WPKH and Taproot addresses.

So the RGB++ examples should support BTC Taproot address to give developers more choices

[ShookLyngs]

I have implemented a local version, but it was based on PR #150, because some new APIs from that PR were used.