Fix Build: Adds imagej dependency

[nicost]

and add relevant imports to LIghtSheetStackTest. It is unclear if this was the intention. Closes #626.

[ieivanov]

Thanks Nico! I think things break at the Deploy PycroManagerJava.jar to Sonatype OSS step, which only runs when a branch is merged into main (I think). So we are yet to see if these changes have fixed the build bug.

I believe Henry's intention was not to make pycromanager explicitly depend on ImageJ. @henrypinkard is there a better place where the LightSheetStackTests can live?

[henrypinkard]

Yes, Im not sure how I ended up merging this in the first place, but these tests are for manual local testing, and imageJ is just for displaying images. So I've just commented out this class for now in #632

[henrypinkard]

I think things break at the Deploy PycroManagerJava.jar to Sonatype OSS step, which only runs when a branch is merged into main (I think)

Ah yes, I think that is right. I made a new issue for this #633