New FLATTEN/UNFLATTEN_JSON Formula functions

Two new Formula functions have been added:

• FLATTEN_JSON(input, [separator]) - Flattens nested JSON into a new object with a single layer of key/value pairs.

• UNFLATTEN_JSON(input, [separator])- Transforms a single layer of key/value pairs into a nested JSON structure.

In each case, the default key separator is a period or full stop (.)