fix: handle OSS/Edge error message

[alespour]

Closes #147

Proposed Changes

OSS (Edge) returns slightly different JSON payload on error. A small change in handling it makes the client throw expected InfluxDBException instead of NPE.

Tested with OSS aa28302 and Cloud as of today.

Note: no idea why one of the patch lines is only partially covered by test, and the check fails.

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are conventional

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.03%. Comparing base (86db636) to head (cec6408).

Files	Patch %	Lines
...va/com/influxdb/v3/client/internal/RestClient.java	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #148      +/-   ##
==========================================
+ Coverage   88.59%   89.03%   +0.43%     
==========================================
  Files          16       16              
  Lines         859      866       +7     
  Branches      129      131       +2     
==========================================
+ Hits          761      771      +10     
+ Misses         42       40       -2     
+ Partials       56       55       -1     

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[bednar]

@alespour thanks for your PR 👍

LGTM 🚀