feature: scan_progress

[m-schmoock]

It's helpful to track the scan progress state (focus, edge, vseg, hseg, stability...). It enables additional functionality like visible user feedback guidance or autofocus trigger once hseg is reached which I have also put in the pull requests (dmz and android).

This increases user experience because:

• The user does not have to trigger autofocus manually by tapping on the display that may shake the device and decrease detection rate / user experience.
• The user gets visible feedback on 'how good' the card can be currently scanned by a progress bar and guide colors. This helps subconsciously so the user holds the card in a way a successful scan is more likely/sooner to happen.

[m-schmoock]

Note: The build only fails because the required DMZ changes cannot be fetched since they are not merged yet: https://github.com/card-io/card.io-dmz/pull/30

[m-schmoock]

Maybe we leave the color of the guide frame as defined (GREEN) and do the fancy color effect just on the progress bar...

Note: The build still fails because the required DMZ changes cannot be fetched yet since they are unmerged: card-io/card.io-dmz#30

[m-schmoock]

Like this. Updated the progress color behavior. Guide frame color is now unchanged.

Note: The build still fails because the required DMZ changes cannot be fetched yet since they are unmerged: card-io/card.io-dmz#30