fix: preserve text/plain error body in raise_if_error() after stream is consumed

[stvoutsin]

Description

DALServiceError raised by raise_if_error was showing an empty message
Example:
DALServiceError: for https://.../sync

when the caller used the pattern:

data = sq.execute_stream().read()
sq.raise_if_error() 

The root cause seemed to be that execute_stream returns the raw response stream without reading the body.
If a caller consumed that stream before calling raise_if_error the response_text that DALServiceError.from_except reads was empty because presumably the underlying buffer was already exhausted.

Fix

The fix reads and caches the response body in the exception handler, before the raw stream is returned to the caller. This ensures response.text remains available when raise_if_error is called later regardless of whether the caller has already read the stream.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.63%. Comparing base (c813d4a) to head (71ee099).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #736   +/-   ##
=======================================
  Coverage   82.62%   82.63%           
=======================================
  Files          91       91           
  Lines       10287    10286    -1     
=======================================
  Hits         8500     8500           
+ Misses       1787     1786    -1     

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[msdemlei]

Hu. That's too magic for me. How would this local reference "cache" the response body? I've not researched the implementation of the content attribute in requests; it probably reads the stream as a side effect?

If that's what it is, there should at least be a comment to that effect, but frankly I'd like that to be a lot more explicit. Do we have a strong reason to not digest the respone content to a user-accessible message right here?

[stvoutsin]

Ok I don't disagree with that take.
The initial approach of accessing response.content worked because requests caches the body as a side effect, but that's implicit and probably fragile.

I've updated the fix to build the DALServiceError eagerly in execute_stream while the response body is still available, rather than deferring to raise_if_error.
Now raise_if_error will just re-raise the constructed exception so there should be no timing dependency on stream consumption now.

Does this seem like a better approach?