Add Codecov for code coverage

[ricoberger]

• I added a CHANGELOG entry for this change.
• I adjusted the corresponding documentation for this change.
• I adjusted the values.yaml file and the documentation for all values.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (main@7e06566). Click here to learn what that means.
The diff coverage is n/a.

@@          Coverage Diff           @@
##             main    #257   +/-   ##
======================================
  Coverage        ?   7.06%           
======================================
  Files           ?      88           
  Lines           ?    7417           
  Branches        ?       0           
======================================
  Hits            ?     524           
  Misses          ?    6881           
  Partials        ?      12           

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