2-12 Data Source Update

I'm adding DataSource scriptable objects to make it easier to get game data into the user interface.

The way it works is you create a source for say an XML file. You fill in the details and can then use the populateDropdown script to make a dropdown with all the values from whatever field you select - for example, all the ship names in a ships.xml file.

I also added display code so the dropdown, when selected, will display a summary of the selected object. This can be configured in the datasource object.

Its still a wip , but I wanted something that worked well for my starfire project where players will be customizing their ship before play.