The multiCheckbox filter popup in the Grid sorts its distinct-value list using JavaScript's native string comparison, which orders characters by Unicode code point. This produces correct results for ASCII-only data but breaks for any locale whose alphabet includes characters outside the ASCII range (Turkish İ/Ğ/Ş/Ö/Ü/Ç, German ä/ö/ü, Czech/Polish diacritics, etc.).

The request is to sort the filter item list using locale-aware comparison (`String.prototype.localeCompare`) so that values appear in the correct alphabetical order for the active language, or provide a custom way to order the filter options.