Add E2E test to perform code suggestion using the Web IDE

This issue is to consider an E2E test for Code Suggestions performed from our WebIDE.

The test would live in the following directory (or EE equivalent): https://gitlab.com/gitlab-org/gitlab/-/tree/master/qa/qa/specs/features/browser_ui/3_create/web_ide?ref_type=heads

Related ask https://gitlab.com/gitlab-org/modelops/applied-ml/code-suggestions/ai-assist/-/issues/252

/cc @nprabakaran