Feature Request: Disable possibility of modifying the files extensions

[DS-INRAE]

Overview of the Feature Request
As an installation admin, I can be sure that the extensions of the deposited files remain unchanged by the user, in order to avoid mischievous deposits "smuggled" passed file extension filters (see related issues).

What kind of user is the feature intended for?
(Example users roles: API User, Curator, Depositor, Guest, Superuser, Sysadmin)
Depositors are affected as they are prevented from editing their files extensions (which also avoids typos),
but the main target benefiting the feature are the installation admins.

What inspired the request?
Discussion about issue :
#10006
and potential ways to bypass such filter.

What existing behavior do you want changed?
When renaming files (API or UI), not being allowed to change the extensions of the files.

Any open or closed issues related to this feature request?
This issue is originated from the discussion in this issue:

• Display deposited (rather than ingested) copy of tabular files  #7956
  This issue is a step towards this issue :
• Feature Request/Idea: Reject files with specific extensions #10006

[pdurbin]

This should probably be configurable in case some installations want to preserve the existing behavior of letting users change file extensions. However, maybe it should be the new default.

[qqmyers]

The current code lets you change the extension of the original file (no ingest) or in the ingested case, only the ingested file extension and not the original. That seems like a weird thing to maintain unless there's real-world use. At QDR, we've gone ahead to display the original file (as in #7956) which makes it even stranger to allow changing the extension of the ingested file. If display of the original file is desired in the community version, I'm not sure that maintaining backward compatibility makes sense - i.e. either extensions shouldn't be changeable or you should only be able to change the original file extension, or we'd need the ability to allow both the original and ingested extensions to be changed, etc. It's messy enough that it might make sense to poll the user base and see if anyone has changes to the original or ingested files in their databases.