Uploading a new version while the old version is unapproved causes issues

[RainOrigami]

The old version stays unapproved when the new version gets approved and messes with the filters.
Also there is no indicator (eg. amber version string) that shows that a previous version is unapproved.
It will probably also not appear in the changelog, or if it does, it'll be missing from the downloads which is confusing.

Some solution is required to either overwrite the previous unapproved version if a new version is uploaded before approval. But this requires some mechanism to tell the moderators since they could be in the process of approving while a new version is uploaded, which then gets approved by accident.`