Enable type-ahead searching of grantees and non-grantees

[pamlo412]

User story:
As a TTA Specialist completing an Activity Report, I want to be able to start typing the name of a grantee or non-grantee in the "Who is this activity for?" dropdown so that I can find and select it faster.

Acceptance criteria:

• when a user starts typing letters into the "Who is this activity for?" dropdown, the list filters to show matching options.

Assumptions:

• we don't need separate stories for type-ahead on grantees and non-grantees because the capability need only be implemented once to work on both lists
• implementing type-ahead for the non-grantee options doesn't have as much UX impact because that list is short enough to view all options at once; but it still has value in making type-ahead consistently available as a way to search and select via your keyboard (i.e. it's good for accessibility)

Exclusions:

• pulling the non-grantee options from the database Display non-grantee options pulled from database #164
• pulling the grantee names and grant IDs from the database Display Grantee Names and Grant Numbers pulled from database #163
• selecting multiple grantees or non-grantees Select multiple grantees or non-grantees for one activity report #166

[rahearn]

This should already be taken care of via #128 (typing filters list in the multiselect) and #163 and #164 (populating the options in the first place)

[pamlo412]

Closing per discussion at grooming