Automatically renaming old filenames when enforcing windows filenames

[sorbaugh]

As an enhancement of #51608 , we should also add this feature to an Admin page so it's not just "hidden" as an occ command.

It would be good to have a UI for this. These are the additional requirements:

• When an admin enforces windows compatible filenames, inform the user about the consequences
• Create a frontend to execute renaming of files.
• an option to start right away or offload to night times (cron)
• batching for possible huge amount of changes. like 100 per run or so (not to overload the sync clients)
• Show a preview or listing of how many files get changed (This is similar expensive as doing the renaming thus not possible in the UI)