Invoice Dashboard shows incorrect decimals for Invoice with unknown currency

[MantisClone]

Problem

The Invoice Dashboard defaults to using 18 decimals to display the Expected Amount when the currency is unknown and not included in the supported currencies list.

It should not display incorrect data.

Solution

• Re-enable the default currency list. It was disabled when the currencies parameter switched behavior to override from append in feat!: Override Parameter for Currencies and Payment Chains in Invoice Dashboard and Create Invoice Form #242
• Display "Unknown" for Expected Amount if the currency is not in the supported currencies list.
• Add a tooltip that says "Cannot calculate the expected amount due to unknown decimals"