feat(auth): Revamp authentication setup (#7387)

* chore: Clean up authentication middlewares

* chore: Rename AuthUser to AuthIdentity

* feat: Define link between user, customer, and auth identity

* feat: Use links for auth, update auth context content

* fix: Adjust user create command with new auth setup

* fix: Make auth login more dynamic, review fixes

* fix: Change test assertions for created by

packages/modules/auth/src/models/auth-identity.ts

@@ -0,0 +1,53 @@
+import {
+  BeforeCreate,
+  Entity,
+  OnInit,
+  OptionalProps,
+  PrimaryKey,
+  Property,
+  Unique,
+} from "@mikro-orm/core"
+
+import { generateEntityId } from "@medusajs/utils"
+
+type OptionalFields = "provider_metadata" | "app_metadata" | "user_metadata"
+
+@Entity()
+@Unique({
+  properties: ["provider", "scope", "entity_id"],
+  name: "IDX_auth_identity_provider_scope_entity_id",
+})
+export default class AuthIdentity {
+  [OptionalProps]: OptionalFields
+
+  @PrimaryKey({ columnType: "text" })
+  id!: string
+
+  @Property({ columnType: "text" })
+  entity_id: string
+
+  @Property({ columnType: "text" })
+  provider: string
+
+  @Property({ columnType: "text" })
+  scope: string
+
+  @Property({ columnType: "jsonb", nullable: true })
+  user_metadata: Record<string, unknown> | null
+
+  @Property({ columnType: "jsonb" })
+  app_metadata: Record<string, unknown> = {}
+
+  @Property({ columnType: "jsonb", nullable: true })
+  provider_metadata: Record<string, unknown> | null = null
+
+  @BeforeCreate()
+  onCreate() {
+    this.id = generateEntityId(this.id, "authid")
+  }
+
+  @OnInit()
+  onInit() {
+    this.id = generateEntityId(this.id, "authid")
+  }
+}