Improve keyboard behavior in the advanced device search

[lawik]

Enter and Tab now complete suggestions the way you'd expect from a command palette, instead of requiring arrow-key navigation first:

• Tab accepts the highlighted suggestion, or the first one
• Enter does the same while mid-word (a non-empty prefix), so typing "hea" + Enter gives "health" rather than running a failed search
• Enter on a structurally incomplete query (mid-term, dangling and/or, unclosed paren) advances to the next slot and shows its suggestions - e.g. out of a finished "like" operator and into the value - instead of submitting a query the server is guaranteed to reject
• Enter on a trailing unterminated string closes the quote and submits
• A finished query still submits with Enter even while the "and"/"or" hints are showing; Escape-dismissed suggestions are never accepted