LP 1780660: Add more workstation functions to OpenILS::Utils::TestUtils.

LP 1780660: Add more workstation functions to OpenILS::Utils::TestUtils.

Add methods find_or_register_workstation($name, $lib) and
find_workstation($name, $lib) to OpenILS::Utils::TestUtils.  These can
be used when writing tests or other scripts to find or create
workstations.

The following Perl live tests were updated to use the new methods
rather than their hand-rolled versions:

* 14-lp1499123_csp_ignore_proximity.t
* 18-lp1592891_sip_standing_penalties.t
* 19-lp1306666-abort-transit-copy-status.t
* 25-lp1694058-multiple-hold-placement.t

Testing this is very simple:

1. Install Evergreen from this branch.
2. Load the Concerto dataset.
3. Start Evergreen services with osrf_control.
4. cd to the perlmods source directory.
5. Do 'make livecheck' and see that all tests pass, particularly the 4
   mentioned above.

Signed-off-by: Jason Stephenson <jason@sigio.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>