[TS3-Workaround] Allow text-messages to be sent to any channel

[MarkL4YG]

TeamSpeak 3 does not allow any type of client to send channel-scoped messages to any channel than the one the client is currently in. It silently redirects the message into the current channel.
A work-around for this is desired so plugins do not fall over this behavior.
Thinkable solutions are:

• Temporarily joining the channel and sending the message
  • Pro: All clients in the channel receive the message (even those not in the cache for some reason)
  • Con: Answers will not be received when sent into the channel
• Sending the messages to all clients currently know to reside in the target channel privately instead
  • Pro: Answers will be received as they're sent privately too
  • Con: Multiple messages have to be spawned which can cause delays for channels with many clients (Related issue: <tba>)

[MarkL4YG]

@finnWellers What do you think of the possible solutions? Other ideas?

[MarkL4YG]

Pinned since this is a common caveat plugin developers might fall into.