Make create content document location more flexible

Use case: a new document is created that must be placed in a folder that has a specific name. For example the Product documents in GoGreen. They are placed in folders that have names matching their main category, e.g. /products/garden. The names come from a value list.

The editor must be able to choose the right name for the folder. If the folder already exists a document picker can be used, but for values that have no folder yet, the user still should be able to choose the correct name.