lowercase for files

[ksmartinrz]

I'd like to create some kind of a policy or action to either rename files while uploaded by the user or even prevent it to upload when its not in lowercase.
Since I am using the Docker variant, local file system solutions are not an option. I also store data on Azure Storage (and the static website feature) in the background, so case-sensitive mandatory for me. I think the event manager and actions would be the best option for this, but I cannot find any options for lowercase. Is there something I am missing?