Bug 36388: Mouse operation does not work in draggable fields in authority editor

Bug 36388: Mouse operation does not work in draggable fields in authority editor

When using the authority editor in Firefox, it is not possible to set
the cursor or select text from the text field.

This patch mimics the corrections made in bug 35425 for biblio editor.

Test plan:
==========
1. Start editing an existing authority record and try to put the cursor
   with the mouse in the middle of the content of any subfield or to
   select text with the mouse. It should not be possilbe.
2. Apply the patch (reload plack etc.).
3. Repeat p. 1 - everything should work as expected.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>