Create a new tree from form fields, or from importing a tree file.

If importing a tree file as an attachment, must use multipart/form-data content-type, and use the content form field to upload the tree file.

Otherwise if importing a tree file from a URL, must use application/json content-type, and use the contentUrl body content property to specify the path the tree file.

Otherwise if creating a tree from form fields, must use application/json content-type, and use the sourceName, sourceGroup, and name body content properties to specify the tree values.