Prevent Uploading Same File (or fileName) Multiple Times in FileUpload Component

[elson-currentcorp]

It would be nice to introduce a new error type, or prop for rejecting an uploaded file through the FileUpload component if the same file (or file name) already exists.

[anubra266]

@elson-currentcorp you can use validate method.
by using some state or ref to hold the acceptedFiles or rejectedFiles.
Validate method would look like this: