Get rid of ResourcePools dependency

[maxfreu]

That issue maybe comes from not knowing enough, but to me it looks like the resource pool stuff should be decoupled from a camera interface definition. It's not clear why an AbstractAcquiredImage should be some pooled dense array.

[stemann]

Good to give it some thought.

Without having thought too much about it (since some years ago): The reason for the dependency is for integrating cameras into a (soft) real-time system - with low-latency requirements - such that one should expect that images returned from a camera is from some pool of shared images, and the user is expected to call release! to give the image back to the pool - or retain! if the user needs to hold onto the image.