Improve compatibility with ResearchBodies

[Gordon-Dry]

see
https://forum.kerbalspaceprogram.com/index.php?/topic/131808-18x-strategia-v180-2019-10-22/&do=findComment&comment=3856235

Strategia shows strategies for unresearched celestial bodies.

[jrossignol]

As discussed on the ResearchBodies thread, this isn't a bug - the strategies are shown, but they are not available. It would be nice to hide them, but not sure if that is technically possible. Will investigate.