Old images uploads are not displayed in wikis

Before 11.3, old uploads to the wikis were added as regular uploads. After that version, new uploads were added as files in the repository. This means that we can have a lot of wikis with old image uploads, in a mixed environment with old image uploads and images in the repo, and with only images in the repository.

In !48763 (merged), we introduced a bug where we didn't pass the correct context to the wiki when rendering the content. This means that the old image links didn't have the proper namespace.

The workaround would be to manually edit every upload and manually add the project namespace to each one of them, but this can be quite tedious because we have a lot of big wikis and, besides, if the project path changes, we would have to edit all of them again.