Option to merge terms (Term Merge integration)

Rerolled #12 for version 2.0.8

As a reminder - please set the "Assigned" field back to "Unassigned" once you are finished with your changes so others can know you're finished.

While this seems to technically work, the UI doesn't work well with large vocabularies as it tries to load every single term in the vocabulary in FilterExistingTermsSelection::buildEntityQuery(). Maybe it should use an autocomplete field for selecting the destination term, or maybe a paginated list?

Could this please be rerolled as MR for easier review and comments? Also back to NW as of #15. Still a useful feature for sure!

Rerolled as MR.
Still need to work on #15

Thanks, nice work, just some minor comments. ✨ Integration with Taxonomy Manager Needs review also needs to be finished to finalize this.

Patch with MR's last improvements for version 2.0.9

Rerolling patch #22 to fix the error:

Path: /taxonomy_manager/term/1111/edit?destination=/admin/structure/taxonomy_manager/voc/geography. Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException: Could not find '{taxonomy_vocabulary}' request argument, therefore cannot check create access. in Drupal\Core\Routing\AccessAwareRouter->checkAccess() (line 115 of /var/www/html/backend/web/core/lib/Drupal/Core/Routing/AccessAwareRouter.php).

Rerolling patch #23 to allow to see toolbar actions when a user has administer taxonomy permission.

I've tested this patch locally and it works fine.
Moved to RTBC.

Andriy Khomych → credited aurelianzaha → .

Everybody thank you for working on this issue.
Moving it to fixed.

This issue has lead to 🐛 Version 2.0.10 breaks existing installations Needs work .

Automatically closed - issue fixed for 2 weeks with no activity.