DivTree: JSON file

The original approach in #529 (closed) assumed we would reuse the existing RepositoryFile approach to associate tree data with crops. This means that the .json file would be uploaded to the repository to the /crops/{crop.shortName} folder directly.

In this ticket, add support to upload the .json file with the DiversityTreeService and controller. The .json files for different DiversityTree are stored in repository at /divtree/{divTree.uuid}.json.

Replace private String treeFile with RepositoryFile treeFile.

If a new .json file is uploaded, the original RepositoryFile must be deleted.

CropDetails

The UI uses CropDetails.files[] list to find *.json and treats them as Diversity Trees for display.

Extend CropDetails with List<DiversityTree> diversityTrees property and load all PUBLISHED records associated with this Crop.

Part of #528 (closed).