v0.2: Replaced isL7 bool with l7FlowType enum

Signed-off-by: Tushar Tathgur <tathgurt@tathgurtPNQHP.vmware.com>

v0.1: Adding L7 visibility fields to the Ipfix table

- isL7 a boolean field to display if the flow row is application layer.
- httpVals a string value containing json strings containing http flows.