[json] create links for values of format `uri-reference`

When authoring json it'd be great to have a richer experience when referencing other files, without having the overhead of defining a file:// URI whenever this is required (see example below).

I would expect this behaviour by standard when the schema is defining the values as file-references, this is also related to my more pertinent issue in the vscode-yaml repository concerning the handling of k8s kustomize resources (vscode-yaml#559)