Add a way to reject repo content updates if overwrites would occur #7550
Description
Is your feature request related to a problem? Please describe.
One issue we've faced is content in repositories being overwritten (e.g. a package with the same NVA or NVRA overwrites an existing package with a different hash). This is often unintentional and it leads to various problems. One big problem is the old package will be cached and its hash will not match the one in the repo metadata.
Describe the solution you'd like
Sometimes we do want to allow packages to be overwritten so I think adding a flag to the repo modify endpoint and the upload endpoint (when repository is specified) would be the best option. Maybe overwrite? And perhaps it could default to True for backwards compatibility. And False would return a 409 if a user attempts to upload a package that would overwrite an existing one.