Fix crash when importing files after some delay

[GianniCarlo]

Bugfix

• iOS changed at some point, and it now puts the selected files into a temp directory, which is very short lived, and will crash the app when trying to access those files

Related tasks

#1127

Approach

• Check if the incoming files are inside a temp folder, if so, move them to the Documents folder, so our file listener will pick them up and kickstart the same import process

Things to be aware of / Things to focus on

• Looks like there will no longer be a system Inbox folder at the root of the Documents folder