feat: add ability for platforms to define custom login selector ui

packages/hoppscotch-common/src/components/firebase/Login.vue

@@ -6,7 +6,11 @@
     @close="hideModal"
   >
     <template #body>
-      <template v-if="isLoadingAllowedAuthProviders">
+      <template v-if="platform.auth.customLoginSelectorUI">
+        <component :is="platform.auth.customLoginSelectorUI" />
+      </template>
+
+      <template v-else-if="isLoadingAllowedAuthProviders">
         <div class="flex justify-center">
           <HoppSmartSpinner />
         </div>

packages/hoppscotch-common/src/platform/auth.ts

@@ -52,6 +52,13 @@ export type LoginItemDef = {
 }
 
 export type AuthPlatformDef = {
+  /**
+   * Whether this platform shows a custom login selector UI. Used for situations
+   * where we don't want to render the traditional UI and want to replace it
+   * with something else
+   */
+  customLoginSelectorUI?: Component
+
   /**
    * Returns an observable that emits the current user as per the auth implementation.
    *