Create resolvers and controllers for core views (#13624)

Created:
- Services
- Resolvers
- Controllers
- Tests for services
- Integration tests for GraphQL and Rest

Updated the Rest API playground

Added new feature flag `IS_CORE_VIEW_ENABLED`

Updated `viewFilter` `operand` and `view` `type` to be enums rather than
strings and generated migration file.

Closes https://github.com/twentyhq/core-team-issues/issues/1259

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/test/integration/graphql/utils/graphql-test-assertions.util.ts

@@ -0,0 +1,45 @@
+import {
+  BaseGraphQLError,
+  ErrorCode,
+} from 'src/engine/core-modules/graphql/utils/graphql-errors.util';
+
+export interface GraphQLResponse<T extends Record<string, unknown>> {
+  status: number;
+  body: {
+    data?: T;
+    errors?: BaseGraphQLError[];
+  };
+}
+
+export const assertGraphQLSuccessfulResponse = <
+  T extends Record<string, unknown>,
+>(
+  response: GraphQLResponse<T>,
+  expectedData?: Partial<T>,
+) => {
+  expect(response.status).toBe(200);
+  expect(response.body.data).toBeDefined();
+  expect(response.body.errors).toBeUndefined();
+
+  if (expectedData) {
+    expect(response.body.data).toMatchObject(expectedData);
+  }
+};
+
+export const assertGraphQLErrorResponse = <T extends Record<string, unknown>>(
+  response: GraphQLResponse<T>,
+  expectedErrorCode: ErrorCode,
+  expectedErrorMessage?: string,
+) => {
+  expect(response.status).toBe(200);
+  expect(response.body.errors).toBeDefined();
+  expect(response.body.errors).toHaveLength(1);
+
+  if (expectedErrorCode && response.body.errors) {
+    expect(response.body.errors[0].extensions.code).toBe(expectedErrorCode);
+  }
+
+  if (expectedErrorMessage && response.body.errors) {
+    expect(response.body.errors[0].message).toBe(expectedErrorMessage);
+  }
+};