Add ability to support Dataflows with multiple fields/column Alternate Key

[Rameshwar]

Currently, Power App Dataflow works fine while loading lookup columns by defining a single column Alternate Key. However, if we add multiple fields/columns in a single Alternate Key, Dataflows does not support it. Please add this functionality.

Refer below scenario for reference - 

https://powerusers.microsoft.com/t5/Power-Platform-Integrations/Dataflow-errors-with-Alternate-Keys-...