[FEATURE] Suggest Search Terms (Autocomplete)

[DMalone87]

Is your feature request related to a problem? Please describe.
Autocomplete is a common search feature that helps users find what they're looking for more easily. We should adopt this technique for our searches.

Describe the solution you'd like
Add an endpoint that can return suggested search terms for a user who is using the "Omni-Search" bar. The endpoint should accept a string (the unfinished search term) and return suggested search terms.
The suggested searches should be broken down into a few categories:

• Locations
• Officer Names
• Agency Names

Additional context
Search Architecture