Defined proper errors with code and reason in SFU media stack

...tc-sfu/lib/mcs-core/lib/adapters/freeswitch/freeswitch.js

...brtc-sfu/lib/mcs-core/lib/adapters/kurento/.errors.js.swp

...rtc-sfu/lib/mcs-core/lib/adapters/kurento/.kurento.js.swp

...bb-webrtc-sfu/lib/mcs-core/lib/adapters/kurento/errors.js

...b-webrtc-sfu/lib/mcs-core/lib/adapters/kurento/kurento.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/constants/Constants.js

.../bbb-webrtc-sfu/lib/mcs-core/lib/media/MediaController.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/MediaSession.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SdpSession.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/SfuUser.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/UriSession.js

labs/bbb-webrtc-sfu/lib/mcs-core/lib/model/User.js