Add double-buffering to data dispatch in order to avoid extraneous copy of data.

zephyr/modules/owntech_data_acquisition/zephyr/adc/adc.c

zephyr/modules/owntech_data_acquisition/zephyr/adc/adc.h

...odules/owntech_data_acquisition/zephyr/adc/adc_channels.h

...yr/modules/owntech_data_acquisition/zephyr/adc/adc_core.h

.../modules/owntech_data_acquisition/zephyr/adc/adc_helper.h

...odules/owntech_data_acquisition/zephyr/data_acquisition.c

...ech_data_acquisition/zephyr/data_dispatch/data_dispatch.c

...ech_data_acquisition/zephyr/data_dispatch/data_dispatch.h

zephyr/modules/owntech_data_acquisition/zephyr/dma/dma.c

zephyr/modules/owntech_data_acquisition/zephyr/dma/dma.h

...data_acquisition/zephyr/public_include/data_acquisition.h