sat plugin: add beta angle

[axd1967]

Is your feature request related to a problem? Please describe. I'd like to know when a satellite is almost permanently visible.

Describe the solution you'd like The beta angle is the angle between a satellite's orbital plane around Earth and the geocentric position of the sun.

Add a field in the sat info block that shows the beta angle.

Additionally, add a satellite filter that allows to filter for high beta angles. The limit can be entered as a new field ("min beta angle") in the Settings dialog. (Default is 70 degrees.)

Additionally, add a filter to filter for low beta angles (eg to find satellites that will be obscured). -> Combine into a filter that allows to enter minimum/maximum beta angle.

Describe alternatives you've considered

Additional context [Add any other context or screenshots about the feature request here.] (https://en.wikipedia.org/wiki/Beta_angle)

This only tends to happen to satellites in LEO with inclinations between 40-70 degrees. There isn't a whole lot of satellites in that range.

[github-actions[bot]]

Hello @axd1967!

Thank you for suggesting this feature.

[axd1967]

See also https://space.stackexchange.com/questions/4686/how-often-does-the-iss-orbit-align-with-the-day-night-terminator