Use ExposureOutput in METIS

[oczoske]

Use ExposureOutput in img_lm (to be expanded to other modes), see AstarVienna/ScopeSim#603

[oczoske]

I have added ExposureOutput in all modes now. For img_n there is a question of order. I have now put averaging and quantisation (soonish to be replaced by adconversion) before chopnod, but this isn't correct either: already chopped images cannot be represented by uint16 (unless one uses BZERO).

[oczoske]

Trying to sum up where we stand:

• tests are green, after fixing a stupid oversight
• The METIS example notebooks need to be checked and revised, because they do not expect AD_Conversion and with SummedExposure are not unlikely to saturate the detector output.
• The switch from SummedExposure to averaged exposure may be unexpected by some users. It shouldn't affect signal-to-noise ratio and therefore won't change "scientific" results.
• It is not clear how this effect (and AD_Conversion) should work with the ChopNodCombiner (a shortcut effect).

[teutoburg]

👍