User Field: Media - Lock down access to “own” media

[particthistle]

joomla#35863 fixes an issue that prevents the creation of media in a User Custom Field > Media type.

To improve the ability to use that plugin (and probably the Content Custom Field > Media type also) some features can be considered relating to this project.

• restrict registered user to only being able to upload content to a folder for that user (folder named by userid)

• restrict which folders registered users can view to select images. Currently they can see every upload which is not best practice.