UI Tweaks

[fields37]

• [x] Add sign icon to sign button at bottom of issue page
• [x] Make file upload text size decrease at smaller screen widths
• [x] Add some sort of visual separation between the signed credential section and the "verify" button. Figure out how to emphasize that button a bit more.
• [x] Get upload icon to go away in upload field on react build
• [x] Fix QR code size breakpoints
• [x] Make QR toggle default to "compressed" if raw not available
• [x] Don't show both QR error messages at once
• [x] Make sure QR field hides when no codes available
• [x] Fix weirdness with close button on QR scan field, perhaps just need to change z index
• [x] Fix shape of camera window field so it doesn't obstruct rest of QR scan modal

[fields37]

Addressed in #78 When pushed to build, need to confirm the following before closing this issue:

• [x] Icon in file upload drop is for sure disabled
• [ ] QR reader close button and camera window size/shape are working as expected on mobile

[fields37]

Spacing and layout of QR scan modal, especially on mobile, could use a bit more work

[kayaelle]

@fields37 & @dmitrizagidulin - what's the status on this one? Should we close and start new issues for display as needed?

[fields37]

This can be moved into a new issue titled something like "Mobile design for QR scan window". The QR scan interface is currently functional on mobile although a little ugly (as shown below), but breaks (becomes larger than the screen height) when the device is rotated into landscape mode.