feat(medusa, types, core-flows): Add invite endpoints for api-v2 (#6395)

**What**
- Add invite endpoints for simple operations on invites

integration-tests/plugins/__tests__/invites/create-invite.spec.ts

@@ -0,0 +1,55 @@
+import { initDb, useDb } from "../../../environment-helpers/use-db"
+
+import path from "path"
+import { startBootstrapApp } from "../../../environment-helpers/bootstrap-app"
+import { useApi } from "../../../environment-helpers/use-api"
+import adminSeeder from "../../../helpers/admin-seeder"
+import { AxiosInstance } from "axios"
+
+jest.setTimeout(50000)
+
+const env = { MEDUSA_FF_MEDUSA_V2: true }
+const adminHeaders = {
+  headers: { "x-medusa-access-token": "test_token" },
+}
+
+describe("POST /admin/invites", () => {
+  let dbConnection
+  let shutdownServer
+
+  beforeAll(async () => {
+    const cwd = path.resolve(path.join(__dirname, "..", ".."))
+    dbConnection = await initDb({ cwd, env } as any)
+    shutdownServer = await startBootstrapApp({ cwd, env })
+  })
+
+  beforeEach(async () => {
+    await adminSeeder(dbConnection)
+  })
+
+  afterAll(async () => {
+    const db = useDb()
+    await db.shutdown()
+    await shutdownServer()
+  })
+
+  afterEach(async () => {
+    const db = useDb()
+    await db.teardown()
+  })
+
+  it("create an invite", async () => {
+    const api = useApi()! as AxiosInstance
+
+    const body = {
+      email: "test_member@test.com",
+    }
+
+    const response = await api.post(`/admin/invites`, body, adminHeaders)
+
+    expect(response.status).toEqual(200)
+    expect(response.data).toEqual({
+      invite: expect.objectContaining(body),
+    })
+  })
+})