acq SEMCCDStream: do not include anchor acquisition in the time estimation per pixel

now compute the time for each pixel, and add estimated time for the anchor acquisitions
left.
This avoids to bump the time left everytime an anchor was acquired.
driver andorshrk: report the wavelengths in the metadata in m

Values were in nm, although the rest of Odemis thought it was m... leading to
huge wavelengths.