Bug 15023: Allow patron anonymize/bulk delete tool to be limited by branch

Bug 15023: Allow patron anonymize/bulk delete tool to be limited by branch

This patch makes the bulk patron delete/anonymize functionality be limited
by branch. It does so by adding a branch selection dropdown and using the
already defined APIs for filtering by branch.

It makes use of C4::Branches::onlymine for the IndependentBranches use case
and it adds a way to call it from the Branches template plugin.

To test:
- Apply the patch
1) Have a superlibrarian user
- Go to Tools > Batch patron deletion/anonymization
=> SUCCESS: Verify you can pick a branch (or all of them)
- Try doing some operations
=> SUCCESS: Verify the selection is respected, and carried around all steps
2) Have a user with tools/delete_anonymize_patrons permissions
- Set IndependentBranches on
- Go to Tools > Batch patron deletion/anonymization
=> SUCCESS: It picks the librarian's branch and doesn't let us choose another one
- Try doing some operations
=> SUCCESS: Verify the user's branch is respected, and carried around all steps
- Sign off :-D

Sponsored-by: VOKAL
Signed-off-by: Liz Rea <liz@catalyst.net.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>