jaco_description lacks package.xml

[ggould-tri]

Most of the manipulation models subdirectories have package.xml files to allow ROS-style access via the package:// URI scheme.

ggould@tars:~/git/drake$ ls manipulation/models/*/package.xml
manipulation/models/allegro_hand_description/package.xml
manipulation/models/franka_description/package.xml
manipulation/models/iiwa_description/package.xml
manipulation/models/wsg_50_description/package.xml

Note that the jaco_description (and ycb) subdirs are not on that list.

This required a fairly ugly workaround in a downstream project.

FYI @sammy-tri @EricCousineau-TRI

[jwnimmer-tri]

For the record, we have discussed removing all of those package.xml files in lieu of a single package.xml at the root of Drake (#10531). But until we make that change elsewhere, we should be consistent for the jaco.

[jwnimmer-tri]

Fixed by #14134 perhaps?

[EricCousineau-TRI]

Oh yeah, oops!