Promote queryAndCheck/execOrThrow to a shared DB utility class

[mambax7]

Context

Two complementary DB helper patterns exist across the codebase:

1. queryAndCheck() — for SELECTs: wraps $db->query(), checks isResultSet(), returns typed \mysqli_result or throws. Currently duplicated in each module's Common/SysUtility.php.

2. execOrThrow() — for DDL/DML: wraps $db->exec(), checks for false return, throws \RuntimeException. Currently local to htdocs/modules/system/include/update.php as system_menu_exec_or_throw().

Both eliminate the repetitive isResultSet() + instanceof \mysqli_result guard pattern and the unchecked exec() fire-and-forget pattern.

Proposal

Consolidate both into a shared utility, either:

• A static helper class (e.g., Xoops\Database\Helper)
• Methods on XoopsMySQLDatabase itself
• An XMF utility

This would:

• Remove duplication across modules
• Standardize error handling for DB calls
• Make update/migration scripts fail-fast by default

Current locations

• queryAndCheck(): multiple modules in class/Common/SysUtility.php
• execOrThrow(): htdocs/modules/system/include/update.php (as system_menu_exec_or_throw)

Related

• PR Clean-room system menu administration #1666 (system menu clean-room) introduced system_menu_exec_or_throw() after repeated review feedback about unchecked exec() calls