Fix refreshing assertion in SystemInfoView

Fixes #3114

I chose to fix the bug on both layers which were triggering the assertion:

1. ```SystemInfoView::NeedsRefresh``` now properly handles when the selection is a whole system and not just a star
2. The selection and hyperspace target in ```SectorView``` are now initialized to the primary star of the current system, not just the system.

Each of those alone fixes the assertion, but better safe than sorry ;)

Pinging @impaktor