Implement Insta360 video streaming to RTMP

Description

In #461 (closed) we explored a potential implementation of WIP 0007 (additional discussions in #417 (closed), !191 (merged)).

We need to add SRS server to support RTMP and WebRTC layers, and implement a perpetual, network-condition-tolerant streaming from Insta360 to RTMP.

Example script with barebones functionality available in MR !201 (closed), file video2rtmp.py. The example script suffers from random stream/connection failures (did not investigate the causes).

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The script needs to be able to run against an Insta360 DeviceConnection object, and run this loop:

1. Try connecting to a camera
   • In case of connection failure, wait a bit and retry
2. Upon successful connection, start preview stream
3. Launch FFmpeg process and stream this to SRS on some endpoint like /live/device_connection_[ID]
4. In case of any network failures (reliability improvements in #462), clean up properly, and go to 1

Scope

• Implement a script that'll run perpetually

MRs

• !212 (merged)
• whitebox-plugin-device-insta360!28 (merged)
• whitebox-plugin-device-manager!22 (merged)
• whitebox-plugin-flight-management!18 (merged)
• insta360!24 (merged)