[a11y] 11.1.4.11 Non-text contrast

[tschiebel]

audit: https://infinite.owncloud.com/s/qSvYucPltEYUhhc

https://github.com/BIK-BITV/BIK-App-Test/tree/main/Pr%C3%BCfschritte/de
https://www.etsi.org/deliver/etsi_en/301500_301599/301549/03.02.01_60/en_301549v030201p.pdf

Note: Information-bearing graphics and graphic control elements as well as their states should
states should have a contrast of at least 3:1 to adjacent colors.

Personal Space

• Each directory or file in the list has "status" icons,
  which indicate to users whether the file has already been shared, for example.
  Unfortunately, some of these icons do not meet the contrast requirements for
  informative graphical elements.
  

• The frames of the checkboxes do not meet the contrast requirements for graphic
  contrast requirements for graphical control elements.