chore: support dart3, fix queryRaw for InfluxDB Cloud

[bednar]

Closes #106
Closes #121

Proposed Changes

1. Added supports for dart3
2. Fixed queryRaw for InfluxDB Cloud

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• pub run test completes successfully
• Commit messages are in semantic format
• Sign CLA (if not already signed)

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.06 ⚠️

Comparison is base (2529cac) 21.05% compared to head (cbf81da) 21.00%.

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #124      +/-   ##
==========================================
- Coverage   21.05%   21.00%   -0.06%     
==========================================
  Files         117      117              
  Lines        7557     7552       -5     
==========================================
- Hits         1591     1586       -5     
  Misses       5966     5966              

Impacted Files	Coverage Δ
lib/client/flux_transformer.dart	78.51% <100.00%> (ø)
lib/client/query_service.dart	100.00% <100.00%> (ø)

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