Address code review: fix 12 issues in server status command
1. Gate 'Connecting to...' message behind non-JSON output check
2. Fix control flow: each branch handles its own exit explicitly
3. Replace raise typer.Exit(0) with return on success path
4. Move get_client to top-level import (consistent with all CLI modules)
5. Remove redundant quotes from 'str | None' annotation
6. Replace orjson with stdlib json for simple serialization
7. Remove fragile _extract_json test helper (no longer needed after #1)
8. Update test mock target to prefect.cli.server.get_client
9. Use deterministic time mocking via _monotonic reference
10. Add test for api_url is None case
11. Normalize output check with is_json flag
12. Centralize output formatting to reduce duplication
Co-Authored-By: alex.s@prefect.io <ajstreed1@gmail.com>