Draft: Descriptor support to enable taproot wallets

[rage-proof]

Hi,

I just wanted to add add the descriptor and taproot support for eps.
But then it let to more changes as intended that were needed. So I let this PR here and you can use it for later, because it works.

The problem is the legacy wallet is not able to handle taproot addresses.
wallet options:
legacy(berkley) - no importdescriptors, no taproot-addresses in general
new(sqlite) - no importmulti, no importaddresses

This leads to the conclusion that the use of the new-descriptor wallet is mandatory and comes with some obstacles:

• a new wallet needs to be created explicitly with descriptor = true (from v23.0 it is standard)
• the whole wallet needs to be rescanned
• the Bitcoin Core version must be >= v22.0 (I guess)
• labels dont work anymore in ranged descriptors, therefore I removed it

Because of having a current version of Core + creating a new wallet it's a bit much effort for an update.
Maybe the rpc upgradewallet is an option to keep the effort low.