[Echo.Events] several improvements:  - do not init a context structure in case of event publishing;  - checking contexts structure for emptyness in case of handlers execution.
[Echo.Events] several improvements:
 - do not init a context structure in case of event publishing;
 - checking contexts structure for emptyness in case of handlers execution.

EchoAppsTeam/js-sdk,EchoAppsTeam/js-sdk