Change move permissions for more coherence

[virgile-dev]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.
In the making of this PR I was thinking that the current permission setting is confusing.
We allow editors to create sub-docs why not allow them to move docs inside a document where they are editors. I feel we should change the permissions for the move action.
Current rules are :
To "Drag" you must be the owner.
To "Drop" you must be owner or admin of the destination file.
To move to my docs I have to be the owner of the doc

Describe the solution you'd like
My proposal would be
Drag -> at least admin
Drop -> at least editor
Move to my docs -> at least admin or editor only he created the sub-doc

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Discovery, Documentation, Adoption, Migration Strategy
If you can, explain how users will be able to use this and possibly write out some documentation (if applicable).
Maybe add a screenshot or design?

Do you want to work on it through a Pull Request?

[virgile-dev]

@lunika @AntoLC @rl-83 what do you think ?