The currency.dust param has been set to '0.00000546' to reflect the minimum amount of BCHA that the app will send.
To support potential decimal place moves, this figure should be in sats.
This diff deletes the currency.dust parameter, replaces it with currency.dustSats, and parses this value for the arbitrary currency.cashDecimals figure wherever it is used in the app. Unit tests are included to ensure consistent application.