Fix getExtensionPageUrl on Windows

Signed-off-by: Lauri Nevala <lauri.nevala@gmail.com>

src/extensions/registries/page-registry.ts

@@ -44,7 +44,7 @@ export function getExtensionPageUrl<P extends object>({ extensionId, pageId = ""
   const extensionBaseUrl = compile(`/extension/:name`)({
     name: sanitizeExtensionName(extensionId), // compile only with extension-id first and define base path
   });
-  const extPageRoutePath = path.join(extensionBaseUrl, pageId); // page-id might contain route :param-s, so don't compile yet
+  const extPageRoutePath = path.join(extensionBaseUrl, pageId).replace(/\\/g, "/"); // path.join returns \ as separator on Windows and needs to be replaced with /
 
   if (params) {
     return compile(extPageRoutePath)(params); // might throw error when required params not passed