Update of intake F5 BIG-IP

Here is the migration changelog: * Add support of F5 Big-IP APM, LTM, AFM and PSM * Extract the timestamp from event if available * Extract the name of the F5 Big-IP rule applied if available * event.type* = info (currently "undefined") * event.category** = network (currently "Successful Request") * observer.type = firewall (currently "ASM") * observer.product = ASM (currently "undefined") **Remarks:** *The previous value of “event.category” was moved to “event.action” **The previous value of “observer.type” was moved to “observer.product” For questions or assistance, please contact our support team.