fixing upper function for pgsql

[binaryk]

Fixed

• fixing upper function for pgsql
• This should fix Postgres DB search by id error #640

[what-the-diff]

PR Summary

• Improved Sensitivity in Filter Method
  We have made enhancements to the 'filter' function, a part of 'SearchableFilter.php', which now handles data in a case-insensitive manner. This allows for better matching and accurate search results.

• Adapted SQL Column Formatting Based on Connection Type
  To ensure our app works seamlessly across different database systems, we introduced new logic within our code. It adjusts the format of SQL queries depending on the type of database connection used, specifically differentiating between Postgres (pgsql) and others. This ensures better compatibility and smoother operation with various databases.