Add representative image to an Instrument

[agbeltran]

Similar to #241, it would be useful to have a representative image associated with an Instrument to be able to display them in the associated UIs.

[kevinphippsstfc]

A simple fix for this, not requiring images to be stored in ICAT or perhaps a new ICAT component, would be to add an imageUrl field to Instrument. There is already a url field for a web page about the instrument.

[RKrahl]

I like the imageUrl idea. It could be used in any web user interface right away, without even the need to add any code to retrieve and display the image.

[agbeltran]

yes, agreed, it would be great to have imageUrl

[agbeltran]

Discussions in the ICAT collaboration meeting today raised a few interesting points:

• instruments usually don't change and could be considered fairly static
• a single image may not be enough for an instrument, and we might need multiple images