Search bar design consistency

## Context

Make search bars across screens consistent. In the first image you can see the search bar view for the Members screen, add a magnifying glass so that search bar is consistent with the search bar in the Events -> Volunteer Timesheets screen, which can be seen in the second image.

Also, edit the font and size of the header "Members" so it is consistent with Volunteer Timesheets and every other screen.

## Requirements

Add magnifying glass to search bar and ensure similar size/consistency
Edit font/size of the Members header so it is consistent with other VolunTrack screens

## Acceptance Criteria

- [ ] fulfills the above requirements