Simple feature request - Add planet list, or number of planets to the Diplomacy view

v0.77

Case:

• While in the Diplomacy UI view there is no list or total number of planets displayed as a way to gauge the other civilizations general size and expansion.
• The number of planets is available in the 'Data Bank' UI but this requires the player to switch in and out of UI views to get this info.

Enhancement:

• At a minimum, in the Diplomacy UI display a numerical value of the total number of known planets for the civilization
• Optimally, in the Diplomacy UI list the known planets and sizes if there is space to do so without clutter