Allow templates to be used in image_processing roi config

[CeeWeasel]

If at all possible, it would be helpful if templates could be used when configuring the image_processing object.

In the past, I had one image_processing object per camera and manually processed the attributes. I went through the centroid list, compared it to input_numbers, and tied it to sensors and binary_sensors. Since centroids are no longer part of the attributes, I've had to set up multiple ROIs for each preset on each of my cameras. My server can handle the added load, but it is still cumbersome restarting my HA instance every time I need to tweak one of those ROIs.

[robmarkcole]

What do you mean by using template - can you give an example?