Add Section for Commonly Used Objs

[Rockdtben]

When making a map I will probably use space, floor, wall, airlock, etc.... a ton of times.

To complete this issue.

Implement the following.

Object Tree should have a 2 new sections

"Frequently Used" - We should be counting the times that a specific turf,area,obj, etc is selected from the object tree, custom pallette, and frequently used section. Use that information to keep a list of the top 5, 10, 15, 20, you pick... items that were used. Show this information in the Object Tree section above custom pallete by default. Allow for this seciton to be rearranged.

"Custom Pallette" - This is a dropdown where custom pallettes are stored. The user is able to create, delete, and view their pallettes they have made. This window section should be resizable like all other sections. The long term goal is to keep things like eclipse and VS when it comes to window management.