Allow slash in Parse.File names

[GabrielLomba]

Is your feature request related to a problem? Please describe.
I am trying to better organize files uploaded to the server and I can't because of the restriction on this line.

Describe the solution you'd like
I would like to be able to save them with slashes as that would allow a clear folder separation between the files, something that another character does not do as clearly (I am using S3 and it supports this separation).

Describe alternatives you've considered
I am currently having to fork the S3 Files Adapter in order to implement this. Even though a slash may not be supported by all adapters, since it is supported by some, I believe the server should allow the adapter to decide wheter or not that is a valid name.

[milesrichardson]

Related discussion: parse-community/parse-server-s3-adapter#16

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.