core-magistrate: refactor business id

[air1one]

Related to #3257 and #3258

Current business id logic is just an increment based on current businesses registered on wallet manager.
As we've seen with bridgechain id, it can be bug-prone (see PR #3258).

So in my opinion we should decide on another id logic for business id. (for example use a hash from name+website ?)

Would like to have some opinions, thanks !