HSB-445 feature: storing user last login timestamp (#4074)

* feat: lastLoggedOn added in schema and service function

* feat: add lastLoggedOn logic for magic link

* test: update test cases

* feat: add lastLoggedOn in gql model

* fix: nullable allowed in model attribute

* fix: resolve feedback

* feat: user last login interceptor added

packages/hoppscotch-backend/src/user/user.model.ts

@@ -30,6 +30,12 @@ export class User {
   })
   isAdmin: boolean;
 
+  @Field({
+    nullable: true,
+    description: 'Date when the user last logged in',
+  })
+  lastLoggedOn: Date;
+
   @Field({
     description: 'Date when the user account was created',
   })