Restore the ability to edit library paths in the outliner.

Previously it was possible to edit the file path of linked library in the "Blender File" section of the outliner. With the introduction of the "Relocate" operator, the option to directly edit the path was removed, and double clicking on the file path just delivers the message "Warning: Library path is not editable from here anymore, please use Relocate operation instead"

...and now the only option is to navigate via the file browser. While in many cases this is fine, in some cases it's an annoying waste of time. For example when you have a large directory tree that you have to navigate, and all you want to do is just enter in the file path directly.

There are many examples in other applications, as well as in Blender, where the user has the ability to either browse for a file, OR enter in a file path. For example, the render output field in Blender.

It would be much better to have the Outliner Library file path work more like that: an editable path AND a browse button. Why restrict the user in this way?