Fix datachannels

[Ivansss]

• Re-send messages that could not be sent because datachannel was still not opened.
• Do not create multiple datachannels. Send all messages through 'status' datachannel.

[codecov]

Codecov Report

Merging #335 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #335   +/-   ##
=========================================
  Coverage     15.62%   15.62%           
  Complexity      274      274           
=========================================
  Files            18       18           
  Lines          1293     1293           
=========================================
  Hits            202      202           
  Misses         1091     1091

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[nickvergessen]

What issues does this help with?

[Ivansss]

Sometimes some channeling messages were not send because the data channel was still not opened and there was not handler for that situation.

For example here 'videoOn' message was not sent so avatar is still visible.