Without this change, we get an error

```
Warning: Each child in a list should have a unique "key" prop.

Check the render method of `BluetoothCardList`. See https://reactjs.org/link/warning-keys for more information.
BluetoothCard@ionic://localhost/dist/bundle.js:21253:18
BluetoothCardList@ionic://localhost/dist/bundle.js:21666:21
```

With this change, the error does not occur

We currently have two hardcoded beacons in the list. But everybody is going to
have their own beacon for testing. Let's make it possible to add new UUIDs

Changes:
- New field to enter the UUID
- Add button
- When add button is clicked, add new entry with the specified UUID and dummy
  values

Testing done:
Entered two separate UUIDs and clicked "Add"
Two new entries were created in the list

- Creates a new set of fields at the botton of the page for the UUID,
  identifier, major and minor fields
- Adds a new "Add" button
- When the "Add" button is pressed, we add a new UUID entry to the default list
- After the new entry is added, we clear out the old values to prepare for a
  new entry

Testing done:
Added three new entries. They were displayed in the list
e-mission/e-mission-docs#1062 (comment)

e-mission/e-mission-docs#1062 (comment)

Testing done:
- Added values with and without a major and minor value
e-mission/e-mission-docs#1062 (comment)

Instead of the statically coded name/identifier
This involved changing the text size so that we could see the UUID
I wonder if we should make the UUID the subtitle and the major:minor the title

Testing done:
e-mission/e-mission-docs#1062 (comment)

We don't know what the result will look like when there are multiple beacons with the same UUID, so we just stringify and display the result.
We cannot test this without having an actual BLE beacon, so I have added a "fake callback button to simulate a callback"

Changes:
- stringify the result in `didDetermineStateForRegion` and pass it in to
  `setRangeStatus`
- Change the BluetoothCard to display the `device.result` as Card.Content
- Add a new button to fake a callback for a device by getting the delegate and
  invoking the `didDetermineStateForRegion` method on it with the device
- Remove the existing result in the device before invoking the callback to
  avoid nested results

Testing done:
e-mission/e-mission-docs#1062 (comment)

Changes:
- in the monitor callback, launch the range call with the UUID that was found
- change the fake callback to call the range callback 500ms after the merge
  callback
- store the two results separately
- display the two results separately using different background colors