[ICS07] Add test to ensure PacketData keeps proper JSON encoding

[Farhad-Shabani]

Background

When serializing PacketData to JSON, it should be converted to RawPacketData first. Encoding PacketData directly may not yield the same result. Nice to add a unit test for including the proper conversion. Additionally, trim places PacketData is used in our tests.

This originated from a discussion in #741 about whether can drop this serde attribute.