Pannellum WebRTC playback

MRs

• !210 (closed)
• whitebox-plugin-pannellum!5 (merged)

Description

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

We need to fix Pannellum initializing to work properly with WebRTC streams, provided by SRS and loaded by Video.js' WHEP Tech (#464)

Scope

• Make Pannellum work well across all browsers with equirect streams from WebRTC