Add interface definition + stubs for serializer
Add implementation for ws_serializer_json_serializer_new()
Add implementation for serialize() callback
Add keys for event serialization
Add interface + stubs + states for serializer state helper(s)
Add implementation for serializer_context_new()
Add helper for generating a new key in the buffer
Add implementation for serialize_event()
Add test file for serializer test
Add test for serializing a ws_message (which is not valid)
Add test for serializing an event
Add test for too small buffer
Add test for event with ctx: obj-id serialization
Close main map in serialize()
Add support for value reply serialization
Add test to test a value reply serialization
Add test for value reply with int reply value
Add support for serializing error replies
Add test for serializing error reply
Restructure getting transaction from an event mapping