Wrong padding applied when currency is explicitly not defined

[vscav]

Today, it is possible to explicitly pass undefined or null to the @currency argument of the AmountInput component.

It is convenient when we want to benefit from the behavior of the amount input without showing any currency information (use case example: the currency information is displayed in another element, next to the input - here we wouldn't want to have the currency displayed twice for the same information).

However, when doing so, the padding stays the same, meaning we have a larger padding-right (i.e. 41px) in the input, that is usually set to be able to display the currency.

If the currency is explicitly set to undefined, null, or to an empty string, we should reset the padding (from 41px to 12px).