When sorting by taggings count, also provide secondary sorting by name

Taggings count don't provide enough order - when too many tags have the same number of uses, the results of sorting are unpredictable and the order keeps changing.

This adds secondary sorting by name, ascending, when the taggings count is the same.
Merge branch 'refs/heads/master' into issue-3278-sorting-taggings-count
Merge branch 'refs/heads/master' into issue-3278-sorting-taggings-count
Merge pull request #1218 from CristinaRO/issue-3278-sorting-taggings-count

When sorting by taggings count, also provide secondary sorting by name