Autocomplete for Knowledge graph roles

[AlexMikhalev]

Since Terraphim KG role graph-based scoring relies on the perfect match, it's not a free text form search; it would be better to add autocomplete from KG automata on the front end. The ideal way forward will be to create a terraphim crate using fst crate and https://blog.burntsushi.net/transducers/ and compile it to wasm to connect to autocomplete functionality on the front end.

[AlexMikhalev]

First prototype committed in autocomplete branch.