Adding the name of the asset being edited on the top of the edit/json widget

It is necessary to have the name of the asset being edited somewhere on the right side of the editor. The reason is that at the moment if you have an asset open, and on the list of the assets on the left you click on some other thing, only once (not double click), that object gets the focus but it is not open. Therefore what you see that is selected is not what is being actually edited.

The idea is to add the name of the asses on the top of the edit/json widget.

If we have the name there it will be useful if there are multiple windows open. see #228.