Add parameter -img-subdir and --ocr-subdir in action script when calling process_images.sh

[markusweigelt]

Due to the dynamic configuration possibilities of Kitodo.Production the image and ocr directory is not fixed.

Kitodo.Production

• Select image subdir and ocr subdir in project configuration
• Add placeholders to provide the configuration to the action script
• Adjust the action script and use these new parameter https://github.com/slub/ocrd_manager/blob/ed69e31b8849fbaadfbe9441f0b3a4bbf2290989/process_images.sh#L21-L22