Add queryUsage method to billing services

A new method, queryUsage, has been added to the billing strategy classes and the gateway service to offer usage querying capabilities for Stripe and Lemon Squeezy. QueryBillingUsageSchema has also been introduced in the schema-related changes. Changes also include updates to the functions' comment descriptions. A minor tweak was made to the Button and Link components in the `faq/page.tsx' file.

packages/billing/gateway/src/server/services/billing-gateway/billing-gateway.service.ts

@@ -7,6 +7,7 @@ import {
   CancelSubscriptionParamsSchema,
   CreateBillingCheckoutSchema,
   CreateBillingPortalSessionSchema,
+  QueryBillingUsageSchema,
   ReportBillingUsageSchema,
   RetrieveCheckoutSessionSchema,
   UpdateSubscriptionParamsSchema,
@@ -118,6 +119,21 @@ class BillingGatewayService {
     return strategy.reportUsage(payload);
   }
 
+  /**
+   * @name queryUsage
+   * @description Queries the usage of the metered billing.
+   * @param params
+   */
+  async queryUsage(params: z.infer<typeof QueryBillingUsageSchema>) {
+    const strategy = await BillingGatewayFactoryService.GetProviderStrategy(
+      this.provider,
+    );
+
+    const payload = QueryBillingUsageSchema.parse(params);
+
+    return strategy.queryUsage(payload);
+  }
+
   /**
    * Updates a subscription with the specified parameters.
    * @param params