Fields DTO conversion reworked

[Raalsky]

As we're going to add support for protocol buffers when fetching data we had to add a proper API level and DTOs conversion. Previously we've been using Bravado models directly/JSONs.

Before submitting checklist

• Did you update the CHANGELOG? (not for test updates, internal changes/refactors or CI/CD setup)
• Did you ask the docs owner to review all the user-facing changes?

[codecov]

Codecov Report

Attention: Patch coverage is 89.26316% with 51 lines in your changes are missing coverage. Please review.

Project coverage is 73.90%. Comparing base (45d38f0) to head (e80c971).
Report is 4 commits behind head on master.

Files	Patch %	Lines
src/neptune/api/models.py	92.27%	20 Missing ⚠️
...eptune/internal/backends/hosted_neptune_backend.py	41.66%	14 Missing ⚠️
src/neptune/integrations/pandas/__init__.py	87.75%	6 Missing ⚠️
.../neptune/internal/backends/neptune_backend_mock.py	87.23%	6 Missing ⚠️
src/neptune/api/field_visitor.py	88.88%	4 Missing ⚠️
src/neptune/table.py	95.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1722      +/-   ##
==========================================
- Coverage   77.84%   73.90%   -3.95%     
==========================================
  Files         240      242       +2     
  Lines       12534    12614      +80     
==========================================
- Hits         9757     9322     -435     
- Misses       2777     3292     +515     

Flag	Coverage Δ
e2e	?
e2e-	?
e2e-management	?
e2e-s3	?
e2e-s3-gcs	?
e2e-standard	?
macos	73.81% <89.26%> (-3.95%)	⬇️
py3.10	?
py3.11	?
py3.12	?
py3.7	73.87% <89.26%> (-3.51%)	⬇️
py3.7.16	?
py3.8	?
py3.9	?
ubuntu	73.74% <89.26%> (-4.03%)	⬇️
ubuntu-latest	?
unit	73.87% <89.26%> (-0.13%)	⬇️
windows	72.74% <89.26%> (-4.66%)	⬇️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[Raalsky]

E2E: https://github.com/neptune-ai/neptune-client/actions/runs/8570941113

[szysad]

🚀🚀

[szysad]

LGTM 🚀🚀🚀