File creation cleanup

[BenCookie95]

Summary

• Hide sharing with "anyone" if your organisation has that permission disabled. I searched everywhere but I could not find a way to check this with the v3 SDK, they removed the DomainSharingPolicy field from the about endpoint. The approach to this permission in v3 seems to be that it will tell you if you don't have that permission if you try to apply it to a file, you cannot check beforehand. v2 has the field we need so I decided to use that SDK for that one check. v2 is not deprecated so I think it's safe to use this one time.
• When sharing a file with channel members it's possible that it will fail to share with some users if they are outside your domain but it should not cause the whole function to fail. I fixed that logic so that we inform the file creator, through a DM, about who didn't gain access.
• Better dialog error messages when file creation fails at a certain step.

Tickets

#2
#1

[fmartingr]

LGTM