feat(l10n): add fractionDigits to currency data in localization files

Author: nima-ct

.changeset/lazy-donuts-visit.md

@@ -0,0 +1,8 @@
+---
+'@commercetools-frontend/l10n': minor
+---
+
+In order to support both versions of the same currency with different fraction digits, these changes:
+
+- Extend generated currency locale data to include fractionDigits (decimal precision) for each currency, sourced from currencymap.json.
+- Introduce ZERO_FRACTION_DIGITS_CURRENCY_MAPPING to define which base currencies should have an explicit 0-fraction-digit variant.