request access: when a user requests access to a file and is rejected, that action is saved and should be available via API

[sbarbosadataverse]

At this time, rejected users are not saved in any way on the file level permissions page:

1. This removes and doesn't allow the dataset owner to track their actual numbers of data requests on their restricted file/dataset
2. This doesn't provide the user with a list of previous requests they can track and keep a record of rejected users
3. This has been requested in support tickets into Harvard Dataverse repeatedly.