fix: honor retryMaxAllowedNumber

[evansims]

Description

This PR:

• Ensures the RetryParams class does not permit max_retry to exceed the hardcoded limit of 15 retries, as configured by the SDK Generator.
• Includes a new comprehensive unit test file for the SDK's Configuration class, which was not present before. These tests increase our code coverage substantially.

Other small bug fixes and improvements to the Configuration were made, which I noticed as I was writing the unit tests:

• disabled_client_side_validations was not working reliably and was unnecessarily using the __setattr__ magic method. This introduced a tiny and unnecessary performance hit when making ANY configuration adjustments. I've created a getter/setter for this property to resolve this.
• min_wait_in_ms was not checking for negative values, or indeed if the passed value was an integer at all.
• The api_scheme setter was not validating the assigned string as being either HTTP or HTTPS.

References

• https://github.com/openfga/sdk-generator/pull/333#discussion_r1548802143
• https://github.com/openfga/sdk-generator/pull/337

Review Checklist

• [x] 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]
• [x] The correct base branch is being used, if not main
• [x] I have added tests to validate that the change in functionality is working as expected

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 95.45455% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 69.02%. Comparing base (f18f786) to head (9989f94).

Files	Patch %	Lines
openfga_sdk/configuration.py	95.45%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #87 +/- ## ========================================== + Coverage 68.29% 69.02% +0.73% ========================================== Files 102 102 Lines 8077 8091 +14 ========================================== + Hits 5516 5585 +69 + Misses 2561 2506 -55 ```

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[evansims]

@rhamzeh Updated with your feedback 👍