fix(ourlogs): Use repr instead of json for message and arguments

[colin-sentry]

Currently if you do something like

    python_logger = logging.Logger("test-logger")
    python_logger.error(Exception("test exc"))

It will error, because Exception is not JSON serializable.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.51%. Comparing base (d0d70a5) to head (2b6fcbc).
Report is 8 commits behind head on master.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4227      +/-   ##
==========================================
+ Coverage   79.48%   79.51%   +0.03%     
==========================================
  Files         141      141              
  Lines       15809    15810       +1     
  Branches     2703     2704       +1     
==========================================
+ Hits        12565    12571       +6     
+ Misses       2382     2380       -2     
+ Partials      862      859       -3     

Files with missing lines	Coverage Δ
sentry_sdk/integrations/logging.py	82.89% <100.00%> (+0.11%)	⬆️

... and 4 files with indirect coverage changes

[antonpirker]

Looks good.

I added some more asserts to the test just to show what is actually sent. And we have a safe_repr() that handles error when calling repr() on objects. Just to be safe.