API Product View: In-console Access Testing Tab

## Epic

Part of #526 - Customer PoC Analysis: Missing Features from CONNLINK-1058

## Context

From customer PoC analysis ([CONNLINK-1058](https://redhat.atlassian.net/browse/CONNLINK-1058)), add an Access Testing tab to the API Product details page.

## Requirements

Add an Access Testing tab that provides:

- **In-console request capability** to test API endpoints
- **End-to-end validation** of the API Product
- Simple interface for making test requests and viewing responses

Start by reviewing the API Product details page and the context in epic #526. Define how the Access Testing tab will make requests, validate the API Product end to end, and display responses. Done means the tab is available in the console with a simple request interface and visible results.

Written by the indexing model from the issue text.