Add configuration to choose field suffix

Problem/Motivation

Currently the price fields show the currency code (EUR) as a field suffix but I would like to show the currency symbol (€) instead.
It is shorter and more user-friendly in my opinion.

Proposed resolution

So I'd like to see a configuration option or maybe two options for this:

1. A general configuration to select the default behavior -> currency code or currency symbol
2. Maybe also a configuration option in the field widget, to change it per field if necessary. This should be set to default by default and give you the possibility to force the currency code or symbol for this specific field.