Add CHAPI get() button to V+ front page

[dmitrizagidulin]

Today, the front page of VerifierPlus serves as a general purpose VC Verifier. It has several "input" mechanisms -- ways to upload the VC to get verified (text box for link or json, file upload input, and a QR code scanner).

This issue is to add another input method: a 'Request from Wallet' button that launches a CHAPI get() request. (For people to be able to request a VC from any compatible wallet, and have V+ verify it right there).