[improve]: Change word Key into Reference for Data Storage component

### Improvement target

Cognitive perception of what is behind of label in user interface. It will make component usage more intuitive and won't require reading documentation for such trivial component property.

### Improvement description

ByteChef targets business technologist role or citizen engineer role.
Word Key in User interface does not mean nothing to those roles. As long as CS Engineer or skilled Software engineer knows that Map object entry has key and value they could intuintively understand what is Key. Other guys would just give up the ByteChef.

Instead of Key use word Reference. It fits better the purpose. It is the technical name that Data Storage components uses to reference stored data.

### Observed Version

1.1.0