E2e alert triggers email notification

Description of the test

New E2E test for New alerts can send email notification to maintainer and owner users

Maintainer user

1. Login as admin, create new user via API
2. Create new project via API, add user to project as MAINTAINER
3. Navigate to Project Settings -> Monitor -> Alert settings -> Enable send email notification
4. Setup and send test alert for HTTP Endpoint integration
   • Verify user receive email with title <project_name> | Alert: <alert_title>
5. Repeat 1 - 3, Setup and send test alert for Prometheus integration
   • Verify user receive email with title <project_name> | Alert: <alert_title>

Owner user

1. Login as admin, create new user via API
2. Create new project via API, add user to project as OWNER
3. Navigate to Project Settings -> Monitor -> Alert settings -> Enable send email notification
4. Setup and send test alert for HTTP Endpoint integration
   • Verify user receive email with title <project_name> | Alert: <alert_title>
5. Repeat 1 - 3, Setup and send test alert for Prometheus integration
   • Verify user receive email with title <project_name> | Alert: <alert_title>

Checklist

• Confirm the test has a testcase: tag linking to an existing test case in the test case project.
• Note if the test is intended to run in specific scenarios. If a scenario is new, add a link to the MR that adds the new scenario.
• Follow the end-to-end tests style guide and best practices.
• Use the appropriate RSpec metadata tag(s).
• Most resources will be cleaned up via the general cleanup task. Check that is successful, or ensure resources are cleaned up in the test:
  • New resources have api_get_path and api_delete_path implemented if possible.
  • If any resource cannot be deleted in the general delete task, make sure it is ignored.
  • If any resource cannot be deleted in the general delete task, remove it in the test (e.g., in an after block).
• Ensure that no transient bugs are hidden accidentally due to the usage of waits and reloads.
• Verify the tags to ensure it runs on the desired test environments.
• If this MR has a dependency on another MR, such as a GitLab QA MR, specify the order in which the MRs should be merged.
• (If applicable) Create a follow-up issue to document the special setup necessary to run the test: ISSUE_LINK
• If the test requires an admin's personal access token, ensure that the test passes on your local environment with and without the GITLAB_QA_ADMIN_ACCESS_TOKEN provided.