Bump iviewer 0.16.0

[will-moore]

Frances was hoping to get this in the next release. Is it possible to deploy onto idr-next?

cc @dominikl

[sbesson]

Deployed by running idr-omero-web.yml followed by idr-omero-readonly.yml (see #436 for the rationale) against prod126. Can you check this works as expected?

[francesw]

I'm experiencing a caching issue with some images. But with non-cached images, it is working as expected.

[dominikl]

Tested with a few images from idr0163, activing more channels. Sometimes I get "Failed to load tiles", but sometimes I get the proper error message. Is that what you meant with caching issues too Frances?
Sorry, ignore my comment. I didn't use private window, in private browser all looks good!

[will-moore]

Seems to be working fine for me too.

[francesw]

I tried in a private window, but I still get the old error message of "Failed to load tiles" with some images. But, yes, I think this is a caching issue.

[sbesson]

Assuming the issues reported above are unrelated to this PR, merging