Admin Page: improve search to handle multiple words

#### Steps to reproduce the issue

1. Go to Jetpack > Settings
2. Search for "Facebook": the sharing module appears in the results.
3. Search for "Facebook sharing": no results.

Ideally I think the search results should match any module that includes either Facebook **or** Sharing in this case.

Start at the Jetpack > Settings admin search entry point and reproduce the difference between searching for “Facebook” and “Facebook sharing.” Trace how the query is matched against modules, then verify that a multi-word search returns modules containing either term, including the sharing module.

Written by the indexing model from the issue text.