[Feature] - create new query to fetch bank list

[islandbitcoin]

create new query to fetch bank and bank branch list from ERPNext.

[brh28]

Grooming notes:

1. Public query supportedBanks
   Returns a List of `{ name: String }
2. Banks are managed in erpnext. Call the ErpNext api to fetch Bank list. How to fetch bank branches from ErpNext? Hopefully, one call to get all branches that we merge with Banks

[linear]

ENG-29

[brh28]

#269