Feature request: Enable published workflow filtering by owner

[lldelisle]

Would be super cool to be able to filter published workflow by owner.
@mvdbeek

[lldelisle]

And/Or highlight IWC workflows.

[nomadscientist]

and be able to search under 'Shared workflows' through ALL workflows (across instances). It could have a column titles 'instance' and they can say where they are (usegalaxy.eu, .org, etc.). Then users can search on a theme across all public instances not just theirs

[davelopez]

xref #16607 :)