Enable "AND" for search interface

[ArtPoon]

For example, to search for B.1.1.7 and Canada

[ArtPoon]

We had some discussion about use cases and whether to limit users to a single AND operation, or unlimited AND. Decided to mothball this feature addition for now.

[ArtPoon]

@GopiGugan suggested having additional search inputs instead of an AND operator, leaving this for further discussion