Sort autocomplete by Key instead of filter by Key

[will-moore]

See #30.

This PR changes the auto-complete behaviour with respect to the "Attribute" value:

Now, we don't filter search results by Attribute but instead we sort the results by attribute.

This allows workflows like...

• Enter pax6 -> see a bunch of auto-complete results, pick "Antibody: pax6" to search

• Now we want to do a different search for pax6 - this time the auto-complete still shows e.g. "Gene Symbol: pax6" so we can pick that and search.

• We still sort by Key, so if you choose "Antibody" and pax, you will see Antibody results first.

But if you happen to enter pax8, you won't see no results - instead you'll get:

[will-moore]

This is now deployed on idr-testing. cc @francesw

[francesw]

Tested on idr-testing, works well.

[pwalczysko]

LGTM

[sbesson]

Is this meant to get released with prod115? If so, we'll need a release of the app and a PR against IDR/deployment