File template feature for VSCode
## Description
The current Web IDE and the Web Editor (single file editor) offer a "file template" feature that applies a pre-set template to a (ideally new) file. As we transition the Web IDE to use VS Code, we need to consider how that feature will work in the context of the new editor.
## Existing options

## Challenges
1. VS Code offers less when it comes to customization of the UI. We may have to get creative for _where_ this feature goes.
2. As discussed in https://gitlab.com/gitlab-org/gitlab/-/issues/300286 and https://gitlab.com/gitlab-org/gitlab/-/merge_requests/18337#note_615017545, the results from the API are returned ungrouped, which is inconsistent with the repository view / single file editor.
issue