Add implementation for NULL callback
Add implementation for boolean callback
Add implementation for integer callback
Add implementation for string callback
Add implementation for start_map callback
Add implementation of map_key callback
Add implementation of end_map callback
Add implementation of start_array callback
Add implementation of end_array callback
Set callback table
Add key for stack position argument type
Add state for stack position argument type state
Initial json deserializer testing setup
Add test for init/deinit deserializer
Add message allocation in deserialize() callback
Add continueing if we are in an invalid state
Set `is_ready` flag as soon as all bytes of an json object are consumed
Add minimal test (empty string)
Add minimal json object test
Add tests for { "": <null,bool,int,string> }