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/src/engine/workspace-manager/dev-seeder/core/utils/seed-feature-flags.util.ts

@@ -60,6 +60,11 @@ export const seedFeatureFlags = async (
         workspaceId: workspaceId,
         value: true,
       },
+      {
+        key: FeatureFlagKey.IS_CORE_VIEW_ENABLED,
+        workspaceId: workspaceId,
+        value: false,
+      },
       {
         key: FeatureFlagKey.IS_TWO_FACTOR_AUTHENTICATION_ENABLED,
         workspaceId: workspaceId,