feat: support passing consistency parameter

[ewanharris]

Description

This is an initial attempt at introducing support for the experimental consistency option in the relevant APIs, this is supported on the following APIs:

• Check
• List Users
• List Objects + Streamed List Objects
• Expand
• Read

And the following SDK methods

• list_relations
• batch_check

It was decided that as this is more of a general request option similar to model id, when using the OpenFGAClient it should be provided via the options object so usage is as follows:

response = await fga_client.check(
	ClientCheckRequest(
		user="user:anne", relation="viewer", object="document:roadmap"
	),
	{ "consistency": ConsistencyPreference.HIGHER_CONSISTENCY },
)

References

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 70.47619% with 31 lines in your changes missing coverage. Please review.

Project coverage is 68.74%. Comparing base (360c2e0) to head (4af82ea).
Report is 141 commits behind head on main.

Files with missing lines	Patch %	Lines
openfga_sdk/models/consistency_preference.py	38.00%	31 Missing ⚠️

❌ Your project status has failed because the head coverage (68.74%) is below the target coverage (80.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #113      +/-   ##
==========================================
+ Coverage   68.72%   68.74%   +0.01%     
==========================================
  Files         119      120       +1     
  Lines        9665     9770     +105     
==========================================
+ Hits         6642     6716      +74     
- Misses       3023     3054      +31     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.