Fix support for currency, missing custom fields

#### What's this PR do?

- Prevent failure if a custom field (multi-select) cannot be mapped to a value
- Add support for currency which is internally a Float.

#### How should this be manually tested?

Make a custom field(type: 'nitpick'/ multi-select) in PLD, add some values and try to use those fields.
Make a currency field in PLD, try to use it.