Convert wei to mutez, rejecting any sub-mutez remainder instead of flooring it away.
amount in wei, from parseAmount
SubMutezPrecisionError if wei is not a whole number of mutez
wei
InvalidAmountError if wei is worth more than 2^63 - 1 mutez, the Michelson mutez bound
InvalidAmountError
Convert wei to mutez, rejecting any sub-mutez remainder instead of flooring it away.