Update js-sdk usages around Buffers to avoid needing Buffer polyfill

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/views/elements/crypto/VerificationQRCode.tsx

@@ -12,7 +12,7 @@ import QRCode from "../QRCode";
 
 interface IProps {
     /** The data for the QR code. If `undefined`, a spinner is shown. */
-    qrCodeBytes: undefined | Buffer;
+    qrCodeBytes: undefined | Uint8ClampedArray;
 }
 
 export default class VerificationQRCode extends React.PureComponent<IProps> {

src/components/views/right_panel/VerificationPanel.tsx

@@ -46,7 +46,7 @@ interface IState {
      * We attempt to calculate this once the verification request transitions into the "Ready" phase. If the other
      * side cannot scan QR codes, it will remain `undefined`.
      */
-    qrCodeBytes: Buffer | undefined;
+    qrCodeBytes: Uint8ClampedArray | undefined;
 
     sasEvent: ShowSasCallbacks | null;
     emojiButtonClicked?: boolean;