Creating a single-file artifact through the UI creates an artifact without partial naming

To reproduce:

1. Enter UI -> Releases -> Upload
2. Upload a random file (not an artifact)
3. Give it a name

The name specified becomes the name of the artifact, but does not become the name of the single-file update. IOW installing it wipes out all other version information, like it was in Mender 2.5. If compared with a manually generated single-file artifact, we can see that the rootfs-image.single-file.version Provides key, as well as the "Clears Provides" field is missing.

Presumably this is because the mender-artifact being used on the server side has not been updated to 3.5.

Acceptance criteria:

• Single-file artifacts generated on the server must get the "rootfs-image.single-file.version" Provides key and the "rootfs-image.single-file.*" Clears Provides key.
• Checklist item added to release checklist to check this on the next release.