The `sqlpage.variables()` function previously allowed duplicate keys
when GET, POST, and SET variables of the same name were present. This
commit ensures that the returned JSON object contains only unique keys,
with precedence given to SET variables, then POST, then GET.
* simplify SQL test files
- Simplified SQL test files by removing unnecessary components and restructuring queries to focus on expected vs actual results.
- Updated the request handling in `run_sql_test` to differentiate between JSON and HTML responses based on test file content.
- Enhanced error handling and assertions for both JSON and HTML responses to improve test reliability and clarity.
- Removed redundant code and improved readability in the test execution flow.
* move more tests to the new expected/actual format
* migrate more tests to the expected/actual format
- Changed references in various test files to point to the new `simple.sql` instead of the outdated `it_works_simple.sql`.
- Removed several obsolete SQL test files that are no longer needed, streamlining the test suite.
- Updated assertions and request paths in the test cases to reflect the new structure and improve clarity.
* Enhance error handling in SQL tests and update SQL syntax
- Added a new function `format_error` to improve error reporting in SQL test assertions, capturing detailed error descriptions and backtraces.
- Updated SQL syntax in `sqrt.sql` to use `INT` instead of `integer` for consistency with SQL standards.
* sqrt test
Ophir LOJKINE