Merge branch 'number-formatt-to-js-framework' into 'master'

[ADD] Number formatter to JS framework

See merge request allianceauth/allianceauth!1756

docs/development/custom/framework/js.md

@@ -122,3 +122,44 @@ const merged = objectDeepMerge(target, source1, source2);
 
 console.log(merged); // {a: 5, b: {c: 6, d: 3}, e: 4}
 ```
+
+### numberFormatter()
+
+Formats a number according to the specified locale.
+Usage:
+
+In your template get the current language code:
+
+```django
+{% get_current_language as LANGUAGE_CODE %}
+```
+
+Then use it in your JavaScript code:
+
+```javascript
+/* global numberFormatter */
+
+const userLocale = '{{ LANGUAGE_CODE }}'; // e.g., 'en-US', 'de-DE'
+const number = 1234567.89;
+
+const formattedNumber = numberFormatter({
+    value: number,
+    locales: userLocale,
+    options: {
+        style: 'currency',
+        currency: 'ISK'
+    }
+});
+
+console.log(formattedNumber); // e.g. "ISK 1,234,567.89" or "1.234.567,89 ISK" depending on locale
+```
+
+#### numberFormatter() Parameters
+
+- `value`: The number to format.
+- `locales`: The locale(s) to use for formatting (e.g., `en-US`, `de-DE`, `['en-US',
+'de-DE']`). If not provided, the browser's default locale will be used and any
+  language settings from the user will be ignored.
+- `options`: Additional options for number formatting (see [`Intl.NumberFormat` documentation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat))
+  - `minimumFractionDigits` is set to 0 by default if not provided.
+  - `maximumFractionDigits` is set to 2 by default if not provided.