Donor Lookup Feature -- Scanner Functionality

## This is an issue spawned from #193

#### Note: First two subtasks 1. and 2. will implement a lot of the features in the current 'Scanner' functionality.
- [ ] On a click, the 'Scan' button will load a window/prompt that loads the Quagga camera scanner, a barcode form input, and a 'Lookup' button.
- [ ] From the newly-opened 'Scan' window, a user can scan/input a barcode.
- A successful scan/input will return the name of the scanned item via the Scanner API endpoints.
- update a 'Name' variable with the scanned item.
- [ ] When the user presses 'Lookup' button
- Close the 'Scan' Window
- Automatically open the 'Add Item' window
- Populate the 'Name' in the 'Add Item' window with the 'Name' variable.

Original UML Diagram from #193 included for reference to 'Donor Lookup' page.


Read issue #193 and the current Scanner functionality first; no file or test entry point is named here. Verify the Scan window's Quagga/barcode input flow and Scanner API lookup, then confirm completion when Lookup closes it, opens Add Item, and pre-fills Name.

Written by the indexing model from the issue text.