🌟Checkin list should require a search term to display matching attendees

[phtaylor]

ℹ️ Please check if the feature you're requesting already exists in the project's roadmap or issues.

Is your feature request related to a problem? Please describe.

Checkin list should not display the list of attendees that can be browsed.
Displaying the list of attendees is a privacy and security problem.

• Users can see the attendees in the list when the checkin page is opened.
• Checkin in a user is a little too easy and can be done by accident. e.g. Putting the phone in a pocket can checkin an attendee.

Describe the solution you'd like

1. The checkin page should be empty when opened.
2. The user can select between scan a QR code or enter a search string.
3. If a search string is entered and then a 'go' button is pressed, the results are displayed.
4. If the search string is cleared, there should be no results. (a clear button would be helpful.)

The search currently acts like a filter on the attendeeds list, but it should be a search at dispalys only mathing results.

Additional context
Add any other context or screenshots about the feature request here.

[islandmix]

Good points. Should be an easy fix for the developer