GUI: Collection Creator UI

[OOPMan]

• Toolbar in mainview with buttons for actions to be performed on selected Collection(s)
• When creating a Collection, select Properties to add and set values for the them
• Text fields can switch between single-line and multi-line input
• Rich text editor option
• Properties should be grouped using Collections
• Added special top-level Collection for Property grouping Collections
• Plugins for properties to allow for custom editor fields to be used? (e.g. file picker, etc?)
• Allow Plugins to be sorted
• Collection "templates"?