Fix error logs/message for loki-op 6 [1.7 backport]

[jotak]

Backport of #617

We're seeing a lot of errors with "no message found". This is because with Loki operator 6, the json of the error has changed. We need now to look at the "error" field.

Also add more debug logs

[openshift-ci]

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[codecov]

Codecov Report

Attention: Patch coverage is 28.57143% with 5 lines in your changes missing coverage. Please review.

Project coverage is 55.99%. Comparing base (eaddfc2) to head (6f80c0b).
Report is 2 commits behind head on release-1.7.

Files with missing lines	Patch %	Lines
pkg/handler/loki.go	28.57%	5 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           release-1.7     #618      +/-   ##
===============================================
- Coverage        56.00%   55.99%   -0.01%     
===============================================
  Files              193      193              
  Lines             9482     9487       +5     
  Branches          1214     1214              
===============================================
+ Hits              5310     5312       +2     
- Misses            3795     3798       +3     
  Partials           377      377              

Flag	Coverage Δ
uitests	57.70% <ø> (ø)
unittests	51.30% <28.57%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
pkg/handler/loki.go	40.00% <28.57%> (ø)

[memodi]

/label no-qe

[jotak]

merging since the original PR was reviewed and merged