Speaker API changes, removing deprecated mechanisms

Hey there! This update is relatively minor compared to the last version but does ship a new API binary.

Changes:

• added support for 'virtual' speakers, which are speakers that are not actively being validated by the plugin, but still tracked and emit audio
• added a new 'virtual speaker' API, which lets developers turn any block/location into an audio source
  • https://javadoc.openaudiomc.net/com/craftmend/openaudiomc/api/WorldApi.html#registerVirtualSpeaker(int,int,int,java.lang.String,java.lang.String,com.craftmend.openaudiomc.api.speakers.SpeakerType,int,com.craftmend.openaudiomc.api.speakers.ExtraSpeakerOptions...)
  • https://javadoc.openaudiomc.net/com/craftmend/openaudiomc/api/WorldApi.html#unregisterVirtualSpeaker(com.craftmend.openaudiomc.api.speakers.BasicSpeaker)
• Removed old version check mechanisms because it's now provided by the account server, meaning that the plugin no longer requires network access to github.com
• Removed old config options for features that have been dropped long ago
• Added required packet adapters to vistas for the new channel UI in the web client