Bug 14456: (regression test) Holdings fields should be skipped by EmbedSeeFromHeadings

Bug 14456: (regression test) Holdings fields should be skipped by EmbedSeeFromHeadings

This patch introduces a regression test for the situation in which
an itemnumber on a record matches the authid of an authority record
and the current implementation of the EmbedSeeFromHeadings filter
wrongly includes new holding fields with authority data...

To test:
- Apply the patch
- Run:
  $ prove t/db_dependent/RecordProcessor_EmbedSeeFromHeadings.t
=> FAIL: The test 'Holdings fields not processed to introduce See-from heading'
   fails.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>