* refactor: remove a few uses of native_mate/gfx_converter.h
* refactor: deprecate mate::EventEmitter
* refactor: add gin_helper::EventEmitter
* refactor: convert a few classes to use gin_helper::EventEmitter
* refactor: get rid of native_mate_converters/gfx_converter.h
* fix: follow native_mate on reporting errors
* fix: gin is weak at guessing parameter types
* fix: incorrect full class name
* fix: gin::Handle does not accept null
