Optimize camera resolution

Known issue

• Some servers are set to 256kb/s for video streams
• That does not fit Low+Medium quality of a simulcast
• So only Low gets send which is very bad perception-wise
• We should therefore:
  • Check that the default resolution we ask from the browsers fits into the default maxstreambits of the HPB and if needed increase that to be at least of some quality
  • Optimize the resolution based on known maxstreambits when received from the HPB: https://github.com/strukturag/nextcloud-spreed-signaling/pull/1099
  • Work together with the HPB to allow more maxstreambits in 1-1 cc @fancycode
  • Work together with the HPB to allow a "optimal streambits per conversation", so that a room could e.g. get 10mbps, if one person is only streaming video, everyone sees them in full hd, if 8 people have the video on, everyone gets ~1.25mbps, if 40 people have video on, the math would be 0.25 mbps, but a minimum should be retained to at least fit the Low quality

No files or tests are named. Start by tracing where browser camera resolution and HPB maxstreambits are handled, then review nextcloud-spreed-signaling PR 1099; completion requires an agreed resolution strategy and coordination with the HPB for the listed simulcast and conversation bandwidth cases.