Welcome to the Tiled forum, @fighterwing989!
At the moment there isn’t. The object type definitions were introduced specifically for objects, which were initially the only things that had a “type” field. Later a “type” field was also added to tiles, such that tile objects could inherit it.
However, it would indeed be nice if types, or at least predefined properties, were more generally available and could also be used on layers and tilesets. This is covered by the following issue:
Recently, work is being done on introducing “components”, which are at the moment reusing the “object types”. Initially components can only be added to objects, but this could be more easily enabled for all data types since it doesn’t require the addition of a “type” field. It would also still be an option to generalize the “type” field for all data types, though. This work is being done on the wip/components branch.