Refactor: Improve alias generation and subquery alias handling

This commit addresses several issues related to column alias generation:

1.  **Standardized `SyntaxFactory::createColumn` behavior:**
    The `createColumn` method in `src/Syntax/SyntaxFactory.php` now consistently creates an alias if a string key is provided in the column definition array (e.g., `['my_alias' => 'column_name']`). This applies even if the alias string is the same as the column name. This change resolved multiple test failures where such aliases were expected but not generated by the previous, more restrictive logic.

2.  **Fixed subquery alias derivation in `ColumnWriter`:**
    The `selectColumnToQuery` method in `src/Builder/Syntax/ColumnWriter.php` was updated to correctly handle subqueries (Select objects) passed with numeric keys.
    - Resolved a fatal error caused by an incorrect call to `Select::getFrom()`; it now correctly uses `Select::getTable()` to access the subquery's main table.
    - Implemented logic to derive the column alias from the subquery's main table's alias or name, if available. This fixed critical test failures where aliases like `AS "role"` were missing for subqueries.

These changes have significantly reduced the number of failing tests and resolved critical errors, paving the way for addressing the remaining specific test cases.

Author: google-labs-jules[bot]