Is your feature request related to a problem? Please describe.
On multiplayer creative server, many players save schematics. but it share the same storage space, that's be disturbing because:

• Others users can show and use your schematics.
• Others users can delete your schematics
• OR any users can remove their schematics (to avoid this)

Describe the solution you'd like
With activation into config.yml, sort the schematic into dir for each user (by UUID)
if the parameters (eg: schematics-per-player) if true, /schematics save /schematics list /schematics remove /schematics load prefix directory by `{uuid's player}/'

Describe alternatives you've considered
It's possible to make ACL with File, consider with Database (External or SQLite) to store ACL for each file.
The system may be more complex but more flexible, each player could be add someone for one of this schematics.

Additional context
Feature into FAWE: boy0001/FastAsyncWorldedit#475

WorldEdit is primarily an admin tool so I consider this a bit out of scope. Don't know what the rest of the team thinks, but this feels like it would be better as a separate mod.

What do you think about it ? @me4502 @wizjany
: D

I think the general consensus from our discord discussion is that we're not keen in overcomplicating things on a per-player basis. Tying to uuids has a lot of inherent complications that WE isn't concerned with addressed (like doing player-name lookups and so on). You can already namespace schematics since the file name can include / which translate to a directory structure. Maybe if someone wanted to contribute the ability to do "per-namespace" permissions that would fit better, but I think we're uninterested in forcing name/uuids into this.