feat: add integration tests (#6923)

### Summary

This PR introduces several integration tests, a mix of manually written
tests and those generated using the `generate-integration-tests` Python
script located in the `scripts` folder.

### Tests Added:
- **Authentication tests**: Validating login, registration, and token
handling.
- **FindMany queries**: Fetching multiple records for all existing
entities that do not require input arguments.

### How the Integration Tests Work:
- A `setupTest` function is called during the Jest test run. This
function initializes a test instance of the application and exposes it
on a dedicated port.
- Since tests are executed in isolated workers, they do not have direct
access to the in-memory app instance. Instead, the tests query the
application through the exposed port.
- A static accessToken is used, this one as a big expiration time so it
will never expire (365 years)
- The queries are executed, and the results are validated against
expected outcomes.

### Current State and Next Steps:
- These tests currently run using the existing development seed data. We
plan to introduce more comprehensive test data using `faker` to improve
coverage.
- At the moment, the only mutation tests implemented are for
authentication. Future updates should include broader mutation testing
for other entities.

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/scripts/generate-integration-tests/introspection.interface.ts

@@ -0,0 +1,60 @@
+export interface IntrospectionResponse {
+  data: {
+    __schema: Schema;
+  };
+}
+
+export interface Schema {
+  queryType: { name: string };
+  mutationType: { name: string | null };
+  subscriptionType: { name: string | null };
+  types: GraphQLType[];
+  directives: Directive[];
+}
+
+export interface Directive {
+  name: string;
+  description: string | null;
+  locations: string[];
+  args: InputValue[];
+}
+
+export interface GraphQLType {
+  kind: string;
+  name: string;
+  description: string | null;
+  fields?: Field[];
+  inputFields?: InputValue[];
+  interfaces?: TypeRef[];
+  enumValues?: EnumValue[];
+  possibleTypes?: TypeRef[];
+}
+
+export interface Field {
+  name: string;
+  description: string | null;
+  args: InputValue[];
+  type: TypeRef;
+  isDeprecated: boolean;
+  deprecationReason: string | null;
+}
+
+export interface InputValue {
+  name: string;
+  description: string | null;
+  type: TypeRef;
+  defaultValue: string | null;
+}
+
+export interface TypeRef {
+  kind: string;
+  name: string | null;
+  ofType: TypeRef | null;
+}
+
+export interface EnumValue {
+  name: string;
+  description: string | null;
+  isDeprecated: boolean;
+  deprecationReason: string | null;
+}