WIP Improvements to the inventory interface

I've been working on adding some features to the player's inventory panel:

Current:

WIP:

The idea is, you could run a search for a planet that buys what you're carrying at the highest known price, then optionally, specify that you'd like a return product from the same system (not necessarily the same planet in that system) to a planet in your current system. You could also filter by range (I don't want to travel farther than x), faction (don't land me at a planet owned by x faction), and whether the destination planet is friendly (don't send me somewhere I have to bribe my way onto the planet).

This information is also limited by the knowledge the player already has about commodity prices; goods for planets a player hasn't ever visited won't appear in the search results, encouraging you gently to explore more :)