[Feature Request] Including ways of fetching (currently) unobtainable information.

To my knowledge, it is currently not possible to grab information from DearPyGui regarding the currently set default font or theme tags. I also believe it is not possible to get information regarding which item handler registry an item is bound to.

With the recent 1.0 changes unifying the theme and item handler registry API regarding their "bindings" to other items, it seems fitting to include information regarding an item's bound handler registry in the return of `get_item_info` right alongside "theme". Since the end-user is lead to believe that the default font and theme are application-bound, adding them to the return of the recently-added `get_app_configuration` seems appropriate. However, I think having a new, seperate callable like `get_app_info` returning this information is also a good idea because; it would mirror `get_item_info`, and it would *probably* be added in some fashion later down the road as DearPyGui continues to expand and you expose more and more info regarding the application to end-users.

🙂