Improvements to map drawing

[IntoxicatedPlatypus]

• Draw beacon groups when zoomed out instead of overlapping each individual beacon
  Previous:

Current:

• Stop drawing ship markers within a system when zoomed out of that system, as they would simply overlap the star's marker

• Improve ship trail drawing.

• • Ship trails now have constant width regardless of zoom. When zoomed in this prevents from solid lines being drawn for interstellar ships, while when zoomed out it makes the trails much more visible.
• • Invisible segments (those drawn beyond the map frame) are skipped, while those partially in frame are cut to prevent drawing hundreds of line dashes across the interstellar space.