The layout of the content of core_tag modals don't look okay in BS4 stable

Note: Test on Boost and Clean Tag collections Log in as an admin Go to " Site administration / Appearance / Manage tags " Click on " Add tag collection " Confirm that " Add tag collection " modal comes up Confirm that the form's layout inside the " Add tag collection " modal looks okay MASTER ONLY START Click on " Cancel " Confirm that the modal closes. Click again on " Add tag collection " Click on " Create " without entering anything in the " Name " field. Confirm that you get a validation message that the field is required. MASTER ONLY END Enter something in the " Name " field. Confirm that you can successfully create a tag collection. Adding standard tags Continuing from the previous section, click on the tag collection that you created. Click " Add standard tags " Confirm that " Add standard tags " modal comes up Confirm that the form's layout inside the " Add standard tags " modal looks okay MASTER ONLY START Click on " Cancel " Confirm that the modal closes. Click again on " Add standard tags " Click on " Continue " without entering anything in the " Enter comma-separated list of new tags " field. Confirm that you get a validation message that the field is required. MASTER ONLY END Enter a list of comma-separated list of new tags and click " Continue " Confirm that the tags are created and added to the list. Combining tags Continuing from the previous section, tick at least 2 of the tags that you created. Click on " Combine selected " Confirm that " Combine selected " modal comes up Confirm that the form's layout inside the " Combine selected " modal looks okay Confirm that the first option in the list of the tags to be combined is ticked. Click on " Cancel " Confirm that the modal closes. Click again on " Combine selected " Tick on the second option and click " Continue " Confirm that you see a message that the tags have been combined. Confirm that the option you selected is shown in the tags list and the others have been removed.