Recognise images concurrently in ImageRecognitionModule

Currently, info.magnolia.ai.image.ImageRecognitionModule does everything in a single thread however, the Image recognition services doesn't block us from attempting to recognise multiple images at once thus, this should be done in the module.

Configurable number of threads should be spawned upon the module startup and each thread should execute the flow foreach image.

In addition, on upload of an image the action should delegate to this component and inform user when the process has been done.