As part of DiamondLightSource/mx-bluesky#1318 we need an ophyd_async device that we can use to get the max pixel value from an optical image.

This device should let us do something like:

with init_devices():
    max_pixel_device = MaxPixelDevice("MY_OAV_PREFIX")

await max_pixel_device.trigger()
max_intensity = await max_pixel_device.max_pixel.get_value()

https://github.com/DiamondLightSource/dodal/blob/main/src/dodal/devices/oav/pin_image_recognition/__init__.py does something very similar to this, we should start from there.

Acceptance Criteria

• There is a device I can use to get the max pixel value from an OAV stream