Add environmental conditions to bring in line with OpenSCENARIO 1.x

[caspar-ai]

Describe the feature

Adding environmental conditions to OSI to match some of those already present in OpenSCENARIO 1.x.

Specifically, the following fields are present in the OSC Environment structure:

• Sun azimuth, elevation, and intensity
  • Note this has some relation to the existing OSI 'AmbientIllumination` field
• Cloud state
• Fog bounding box
• Precipitation type
  • Already covered by the existing Precipitation Classification #415 but mentioned here for completeness
• Wind direction and speed

Describe the solution you would like

New fields added to the existing EnvironmentalConditions message.

Describe alternatives you have considered

Existing pattern so no other alternatives considered.

Describe the backwards compatibility

No issues for backwards compatibility, all new fields will be optional.

Additional context

This purpose of this ticket isn't to do full alignment, in particular there are existing disconnects between OSC and OSI where one uses a continuous value and the other uses an enum. That is a more complicated discussion and is already covered by #255 and so is considered outside the scope of this issue.

[HendrikAmelunxen]

Closed; #593 is merged