feat: added context.Context to each handler

feat: small code cleanup

- changed the default message type from Text to Binary. It could be c…

…hanged with TextMessage = true

- added binary message support as a message

- changed behavior for a missing callback. Now the message will be pa…

…ssed to the onMessage handler

- updated dependencies

small refactoring

fix closing the connection when OpClose receive, add test to this case

do not drop connection if process message has error

fixed ping bug (ping closed connection when timeout without reason)

fixed `Channels` function to return a number of real active connections

Channel.Count now returns count of live connections only

- remove connection from channel if error when emit; close conn if er…

…ror when ping