VTL - Analytic operators

Name	Symbol	InMemory	Spark
Analytic invocation		❌	✔️
First value	first_value	❌	✔️
Last value	last_value	❌	✔️
Lag	lag	❌	✔️
lead	lead	❌	✔️
Rank	rank	❌	✔️
Ratio to report	ratio_to_report	❌	✔️