Add GraphiQL Client link to CAP service list page (index.html)

[lochlouw]

Add GraphiQL Client link to service list page (index.html)

Current Behavior

Currently, when GraphQL services are registered in a CAP application, they appear on the generic service list page (index.html), but there's no direct link to access the GraphiQL interface for testing and exploring the GraphQL API.

In contrast, when the Swagger UI plugin is added for OData services, a convenient link to the OpenAPI documentation appears next to each service on the index page.

Proposed Enhancement

Add a GraphiQL client link next to GraphQL services on the service list page, similar to how OpenAPI/Swagger UI links are displayed for OData services.

This would provide:

• Quick access to the GraphiQL interface directly from the service list
• Consistent UX with how other API exploration tools (OpenAPI) are integrated
• Improved developer experience when working with GraphQL endpoints

Example

For a GraphQL service mounted at /graphql, the service list should display something like:

/graphql - [GraphiQL] 

Where clicking [GraphiQL] would navigate to the GraphiQL interface (e.g., /graphql with the GraphiQL UI).

Use Case

Developers frequently need to test GraphQL queries and explore the schema during development. Having direct access from the index page would streamline this workflow, matching the convenience already provided for OData services with Swagger UI.