patch NNBSP number separator out of cultures that use it (fixes #2157)

Dalamud/Utility/CultureFixes.cs

@@ -0,0 +1,45 @@
+using System.Globalization;
+
+namespace Dalamud.Utility;
+
+/// <summary>
+/// Class containing fixes for culture-specific issues.
+/// </summary>
+internal static class CultureFixes
+{
+    /// <summary>
+    /// Apply all fixes.
+    /// </summary>
+    public static void Apply()
+    {
+        PatchNumberSeparator();
+    }
+
+    private static void PatchNumberSeparator()
+    {
+        // Reset formatting specifier for the "digit grouping symbol" to an empty string
+        // for cultures that use a narrow no-break space (U+202F).
+        // This glyph is not present in any game fonts and not in the range for our Noto
+        // so it will be rendered as a geta (=) instead. That's a hack, but it works and
+        // doesn't look as weird.
+        void PatchCulture(CultureInfo info)
+        {
+            const string invalidGroupSeparator = "\u202F";
+            const string replacedGroupSeparator = " ";
+            if (info.NumberFormat.NumberGroupSeparator == invalidGroupSeparator)
+                info.NumberFormat.NumberGroupSeparator = replacedGroupSeparator;
+                
+            if (info.NumberFormat.NumberDecimalSeparator == invalidGroupSeparator)
+                info.NumberFormat.NumberDecimalSeparator = replacedGroupSeparator;
+
+            if (info.NumberFormat.CurrencyGroupSeparator == invalidGroupSeparator)
+                info.NumberFormat.CurrencyGroupSeparator = replacedGroupSeparator;
+                
+            if (info.NumberFormat.CurrencyDecimalSeparator == invalidGroupSeparator)
+                info.NumberFormat.CurrencyDecimalSeparator = replacedGroupSeparator;
+        }
+            
+        PatchCulture(CultureInfo.CurrentCulture);
+        PatchCulture(CultureInfo.CurrentUICulture);
+    }
+}