Bug 6210 - Follow up, Choose framework on merge

Bug 6210 - Follow up, Choose framework on merge

- Adding subtitle to the display of titles to be merged
- Adding a link to preview the MARC record of titles to be merged
- Fixing up markup of form to improve appearance
- Correcting breadcrumbs

Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
(cherry picked from commit 049ac6e2a7182a65cc83cea352ab377c3bec6924)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>
(cherry picked from commit 8b3bb800dd4fcf3107ae261ac5edeb634c6ade9e)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>