feat(cms page): add requirement on locale page show

Author: maximehuran

monsieurbiz/sylius-cms-page-plugin/1.0/config/routes/monsieurbiz_sylius_cms_page_plugin.yaml

@@ -5,3 +5,5 @@ monsieurbiz_cms_page_admin:
 monsieurbiz_cms_page_shop:
     resource: "@MonsieurBizSyliusCmsPagePlugin/Resources/config/routing/shop.yaml"
     prefix: /{_locale}
+    requirements:
+        _locale: ^[a-z]{2}(?:_[A-Z]{2})?$

monsieurbiz/sylius-cms-page-plugin/2.0/config/routes/monsieurbiz_sylius_cms_page_plugin.yaml

@@ -8,7 +8,7 @@ monsieurbiz_cms_page_show:
     methods: [GET]
     requirements:
         slug: .+
-        _locale: ^[A-Za-z]{2,4}(_([A-Za-z]{4}|[0-9]{3}))?(_([A-Za-z]{2}|[0-9]{3}))?$
+        _locale: ^[a-z]{2}(?:_[A-Z]{2})?$
     defaults:
         _controller: monsieurbiz_cms_page.controller.page::showAction
         _sylius: