* fix(ViewportWindowLevel): add null checks for volumeActor in opacity functions
* refactor(ViewportWindowLevel): register histogram worker at module load and optimize scalar data retrieval
* fix(Preclinical4D): add null check for viewportId and set frame rate for cine playback
* fix(getSopClassHandlerModule): handle multiframe dynamic volumes by utilizing metaData for instance retrieval
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Co-authored-by: Bill Wallace <wayfarer3130@gmail.com>