Implement multi-file editing and rendering (Iteration N)
Important: All the new functionality must be implemented behind the feature flag :snippet_multiple_files. Besides, it has to be scoped for users. Therefore, instead of checking if the feature flag is enabled or not (Feature.enabled?(:snippet_multiple_files)), we will check if the feature flag is enabled for specific users (Feature.enabled?(:snippet_multiple_files, user)).
This issue focuses on including multi-file editing and rendering (including adding new files and deleting them).
In gitlab-foss#63499[Navigation.png] is the new design for the entire page and in #14340 (closed) the designs for multi-file editing.
![gitlab-foss#63499[Navigation.png]](https://gitlab.com/gitlab-org/gitlab-foss/issues/63499/designs/Navigation.png){kind=link}
This issue will not cover revisions, forking, and the new actions Clone via HTTPS or Clone via SSH. It will mostly focus on displaying the content from the repository and implementing the multi-file workflow.
Availability and Testing
We can possibly add coverage for multiple file snippets within the existing E2E