Fix `None` derivation path index for custom currencies#464

Draft

vnprc wants to merge 3 commits intocashubtc:mainfrom vnprc:custom_currency

+150-21

Commits on Nov 20, 2024

fix: allow custom currency units to specify derivation path
vnprc
committed
fix: disallow pre-allocated derivation paths from custom currency units
vnprc
committed
fix: add upper limit to CurrencyUnit::Custom derivation path index
vnprc
committed