result: fix bug: paging state taken from PREPARED response instead of RESULT

[wprzytula]

A bug is fixed that when set_use_cached_result_metadata flag is set, then the ResultMetadata would be taken from PreparedStatement including paging_state, effectively yielding empty paging state for every request with the flag set. A related regression test is added.

Pre-review checklist

• [x] I have split my patch into logically separate commits.
• [x] All commit messages clearly explain what they change and why.
• [x] I added relevant tests for new features and bug fixes.
• [x] All commits compile, pass static checks and pass test.
• [x] PR description sums up the changes and reasons why they should be introduced.
• [ ] I have provided docstrings for the public items that I want to introduce.
• [ ] I have adjusted the documentation in ./docs/source/.
• [ ] I added appropriate Fixes: annotations to PR description.

[github-actions[bot]]

cargo semver-checks found no API-breaking changes in this PR! 🎉🥳 Checked commit: 524930905fe649d60dc77da2a56fc7294e0d60da