Fix "connect timed out" error message

• Fix Build Number:

  8.4.1.2109

When CM can't connect to a broker, it displays connect timed out.

1. The error messages should displays full sentences which start with a capital letter.
2. "The connection has timed out." should be displayed instead.
3. It would be even better if more information was displayed to answer user's question "What should I do then?". The additional info could say "Please try again later." or something like this depending on the situation.

Otherwise, even if CM is the best tool in the world, but if it has such amateur error messages, users will not take it serious.

Please improve this and other error messages.