[Part-2] Show requirements list for the project

What does this MR do?

This MR is part-2 in the series of MRs which will add Requirements vue app to list, create and edit requirements under Projects. This feature is currently behind a feature flag which can be enabled via Rails console for a specific project as;

Feature.enable(:requirements_management, Project.find_by_full_path('gitlab-org/gitlab-shell'))

How to check this MR locally?

If you want to try out this MR locally, you'll first have to create a few requirements for the project (gitlab-org/gitlab-shell in this case), and since currently there's no way to create requirements from UI (that comes with #207954 (closed)), you can do so from GraphQL playground on your GDK with following steps;

1. Make sure you're logged in to GDK as a root.
2. Visit /-/graphql-explorer URL.
3. Paste in the following mutation in the query section (top-left textarea) of the page;

mutation createRequirement($createRequirementInput: CreateRequirementInput!) {
  createRequirement(input: $createRequirementInput) {
    clientMutationId
    errors
  }
}

4. Paste in following JSON in query variables section (bottom-left textarea) of the page

{ "createRequirementInput": { "projectPath": "gitlab-org/gitlab-shell", "title": "Sample Requirement" } }

5. Run the query (click ▶️ button) and it will create a new requirement which will be visible under /gitlab-org/gitlab-shell/-/requirements.
   • You can update title from step 4. and re-run the query multiple times to create more requirements.

Screenshots

	List View	Empty State
Desktop
Mobile

Does this MR meet the acceptance criteria?

Conformity

• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #207981 (closed)