Inline shared query params test methods into individual tests

The shared queryParamsStickyTest1-6 methods on ModelDependentQPTestCase
abstracted test bodies behind parameterized helpers, making the tests
harder to follow. Inline each method body directly into the 12 test
methods that called them, substituting the concrete route names and
URL prefixes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: NullVoxPopuli