normalize *.json files

please execute tools/normalize_json.py before committing *.json changes.
packet_data_generator: update of_protocol

for ipv6_flabel and mpls_label.
(https://github.com/FlowForwarding/of_protocol/pull/57)
packet_data_generator: add cases to use all oxm types
packet_data: regen
test_parser: expected json representations for new test cases