Review descriptor feature

[Naviabheeman]

Descriptor feature is used to give the description of scripts in pk(...), pkh(...), sh(...) format. It still has witness support.

1. We need to decide if this feature is useful in Tapyrus.
2. Extend it to support coloured coins.

[Naviabheeman]

In Bitcoin descriptors is a big feature with a separate sqlite db. wallet can be configured to use sqlite and descriptors instead of leveldb and raw scripts. New RPCs like 'deriveaddresses', 'generatetodescriptor' allow using them instead of raw scripts. The feature is very mature and can even be used in the coinbase transaction output to receive block reward. Porting it to Tapyrus-core may be useful only if we plan to use this extensively. It can be used to represent the script in all the layers from Tapyrus-core to the api layers.
Since we are comfortable with the raw bitcoin script I would not recommend this as a feature in Tapyrus-core