Add MQTT alongside OSC to replace it in the long run

[lcb01a]

Add MQTT alongside OSC to replace OSC in the long run OSC in its current form is not a good fit due to multiple issues.

• OSC-Query is needed for multiple applications which itself is only a proposal and not a solid standard. There are issues on how its implemented in VRC.
• MQTT doesn't need OSC-Query, you have a server-client structure natively.
• VRC could run its own MQTT server or connect to one in the network.
• OSC is not widely used, MQTT is used for many different use cases. From IOT devices to inter game server communication. It supports TCP and UDP
• There are way better libraries than for OSC
• Every OSC application can be easily migrated as the path structure is identical and libraries are easily interchangable
• It can be used for worlds too in the future (e.g. mixed reality worlds with interaction between helper applications that run outside of VRC)