LP1848778 Use consistent MARC breaker delimiter

LP1848778 Use consistent MARC breaker delimiter

Use the '$' delimiter in the read-only MARC breaker view for
consistency with the flat text MARC editor to easy copy/paste from one
to the other.

To test
-------
[1] Apply the patch.
[2] Set up two records in a record bucket and initiate a merge. Note
    that when you select a lead record and choose to edit it in
    flat text mode, you can copy and paste fields from the subordinate
    record display without having to change the subfield delimiter
    character.
[3] Mark a record for overlay, perform a Z39.50 search, then select
    a hit and choose the overlay action. Note that you can copy and
    paste fields from the record to overlay when editing the incoming
    record using the flat text editor.

Signed-off-by: Bill Erickson <berickxx@gmail.com>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>