Show 'synonymous' instead of all non canonical tags

Noncanonical tags encompass both unfilterable and synonyms.

There was already a column to show unfilterable tags only.

The 'noncanonical' column was showing unfilterables and tags that had been merged with synonyms (mergers).

Now there is a 'synonymous' column instead, which shows only non-canonical tags that have synonyms.
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-1891-view-synonyms-only
Merge branch 'refs/heads/master' into issue-3278-sorting-taggings-count
Merge branch 'refs/heads/master' into issue-1891-view-synonyms-only
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
Merge pull request #1217 from CristinaRO/issue-1891-view-synonyms-only

Show 'synonymous' instead of all non canonical tags