Support boolean search combination of languages

[nichtich]

By now JSKOS server backend combines multiple languages via boolean OR. There should be a way to combine them via AND.

Current workaround is to get query result (bottom right icon </>) and process with addition tool such as jq (also possible online at https://jqplay.org/). For instance all glossaries with English AND French:

curl 'https://bartoc.org/api/voc?type=http%3A%2F%2Fw3id.org%2Fnkos%2Fnkostype%23glossary' | jq '.[]|select(.languages|any(index("en")) and any(index("fr")))'