AGIPD: handle bad pixel constants with three dimensions with more cells than requested

The exception that started https://redmine.xfel.eu/issues/177981 seems to stem from another place where assumptions are made about the number of cells in a constant matching the number of cells we asked for. This merge request gets rid of that assumption - as long as we get at least as many cells as we asked for, all is good. Also, including fix for addon schema override related issue I just spotted because it got in the way of testing (and should be deployed ASAP, too).

assigned to @hammerd

Ugh, this tranposing business is ugly. But this seems to do the right thing, LGTM.

It's definitely not an elegant solution. For most constants, we could do some automatic guessing based on sizes, but that would be terrible to debug when breaking. And not work at all for LPD at 256 x 256 pixels. Or special constants like thresholds or slopes with special dimensions.

merged

mentioned in commit 698d3db7