Smart tag auto-completion

Text inputs working with tags, like `[tag selector]` in Resource Grid and `[tags editor]` in Gallery, should be able to work with not only full _id_, but also with parts of _title_ in case of dedicated tags (#257). Tags with parents (#255) also should be possible to be found by typing their parent _id_ or _title_.

Start by inspecting the tag inputs in Resource Grid and Gallery, especially the `[tag selector]` and `[tags editor]` paths. Review related issues #257 and #255 to understand dedicated and parent tags. Done means these inputs can find tags by partial title as well as full ID, and parent tags by parent ID or title.

Written by the indexing model from the issue text.