Set the MIME type of the response in the image1Action method of the
ClientController.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Disable the "access token" validation in the ResourceController.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Validate the "access token" in the ResourceController::imageAction method via
the Validation Service of Symfony.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>