fc929842c2 GUI: Move QRImageWidget to its own file-pair (Luke Dashjr)
77851ab682 GUI: Refactor actual QR code rendering into new QRImageWidget::setQR (Luke Dashjr)
Pull request description:
For at least QR-code based pairing of mobile wallets with nodes, it will be desirable to render QR codes even without wallet support.
Therefore, this prepares by moving the QRImageWidget out of a wallet-specific file into its own `qrencoder` file-pair.
ACKs for commit fc9298:
laanwj:
utACK fc929842c2
jonasschnelli:
utACK fc929842c2
Tree-SHA512: 95529a38c0573a4b3f1253fb5f11ca07a5b3a9840ec24acc7d87270212f3c9f7c5b186d9274d297517a3b80494f38a57574fb9730b1574db01688539b987bd91