Fix server integration tests 2 (#10818)

## Context
- Removing search* integration tests instead of fixing them because they
will be replaced by global search very soon
- Fixed billing + add missing seeds to make them work
- Fixed integration tests not using consistently the correct "test" db
- Fixed ci not running the with-db-reset configuration due to nx
configuration being used twice for different level of the command
- Enriched .env.test
- Fixed parts where exceptions were not thrown properly and not caught
by exception handler to convert to 400 when needed
- Refactored feature flag service that had 2 different implementations
in lab and admin panel + added tests
- Fixed race condition when migrations are created at the same timestamp
and doing the same type of operation, in this case object deletion could
break because table could be deleted earlier than its relations
- Fixed many integration tests that were not up to date since the CI has
been broken for a while

---------

Co-authored-by: Charles Bochet <charlesBochet@users.noreply.github.com>

.github/workflows/ci-server.yaml

@@ -170,6 +170,7 @@ jobs:
           - 6379:6379
     env:
       NX_REJECT_UNKNOWN_LOCAL_CACHE: 0
+      NODE_ENV: test
     steps:
       - name: Fetch custom Github Actions and base branch history
         uses: actions/checkout@v4
@@ -183,6 +184,7 @@ jobs:
           echo "BILLING_STRIPE_API_KEY=test-api-key" >> .env.test
           echo "BILLING_STRIPE_BASE_PLAN_PRODUCT_ID=test-base-plan-product-id" >> .env.test
           echo "BILLING_STRIPE_WEBHOOK_SECRET=test-webhook-secret" >> .env.test
+          echo "BILLING_PLAN_REQUIRED_LINK=http://localhost:3001/stripe-redirection" >> .env.test
       - name: Restore server setup
         uses: ./.github/workflows/actions/restore-cache
         with:
@@ -194,15 +196,14 @@ jobs:
           npx nx build twenty-shared
           npx nx build twenty-emails
       - name: Server / Create Test DB
-        env:
-          NODE_ENV: test
         run: |
           PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d postgres -c 'CREATE DATABASE "test";'
       - name: Server / Run Integration Tests
         uses: ./.github/workflows/actions/nx-affected
         with:
           tag: scope:backend
-          tasks: 'test:integration:with-db-reset'
+          tasks: 'test:integration'
+          configuration: 'with-db-reset'
       - name: Server / Upload reset-logs file
         if: always()
         uses: actions/upload-artifact@v4