Add support for HTTP protocol version in AbstractRequest; update JxRe…

[swnck]

This pull request introduces support for specifying the HTTP protocol version in requests, alongside some minor refactoring and test additions. The most important changes include adding a new setVersion method to configure the HTTP version, updating the JxResponse class to handle this new configuration, and adding a test case to validate the functionality.

HTTP Version Support:

• Added a new setVersion method in AbstractRequest to allow users to specify the desired HttpClient.Version for HTTP requests. This method includes validation to ensure the version is not null.
• Updated the JxResponse constructor to include the HTTP version when building the request.
• Introduced a new version field in AbstractRequest with a default value of HttpClient.Version.HTTP_1_1.

Testing:

• Added a new test case getWithVersion in JxRequestTest to verify that the HTTP version can be set to HTTP_2 and that the request executes successfully.

Minor Refactoring:

• Removed extensive inline comments from AbstractRequest to simplify the codebase.
• Added a missing import for HttpClient in AbstractRequest and JxRequestTest. [1] [2]