Jenkins Code Dx Plugin missing permission checks

Jenkins Code Dx Plugin 3.1.0 and earlier does not perform a permission check in a method implementing form validation.

This allows attackers with Item/Read permission to check for the existence of an attacker-specified file path on an agent file system.

Code Dx Plugin 4.0.0 requires Item/Configure permission for this form validation method and ensures that only files located within the workspace can be checked.