Support OpenAPI 3.2 parameter/query model and additional operations

[HavenDV]

Problem

AutoSDK can parse/round-trip OpenAPI 3.2 documents through Microsoft.OpenApi, but the code generation pipeline still appears to ignore several new 3.2 parameter/operation constructs.

Concrete gaps from the current codebase:

• I could not find any handling for ParameterLocation.QueryString
• I could not find any handling for ParameterStyle.Cookie
• operation traversal still walks path.Value.Operations, with no support for 3.2 additionalOperations
• generated request building is specialized for query, path, header, and a subset of existing styles, not the newer 3.2 query-string modeling approach

Why this matters

OpenAPI 3.2 extends how HTTP APIs can model query strings and non-core HTTP operations.
Parsing support in Microsoft.OpenApi is useful, but AutoSDK still needs generator support to avoid silently dropping or mis-modeling valid 3.2 descriptions.

Relevant 3.2 features

• in: querystring
• style: cookie
• additionalOperations on Path Item Objects for methods beyond the fixed operation fields

Requested behavior

• Support in: querystring parameters in generation
• Support 3.2 cookie-style serialization where applicable
• Traverse and generate methods for additionalOperations
• Add tests covering valid 3.2 specs that use these constructs

Notes

This is specifically about 3.2 parameter/operation modeling, not the broader auth work in #47 / #225 / #231.