FeatureInfo: Make it possible for admins to set a hard-coded label when no good attribute values exists on dataset

[jacobwod]

Currently admins can control what is shown in the primary and secondary labels in the new MapClickViewer using these settings:

This gives a nice summary:

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However, not all datasets have relevant fields with information that can be exposed to the user. Still we must display something (both in the list and in the breadcrumbs). The current solution was to grab OpenLayer's FID (feature ID) and make it a label. Not very nice, but it works:

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Due to popular request from multiple organizations, we have now decided that we should let admins set a hard-coded label, if it is preferred. The syntax that we propose is putting the label inside double quotation marks.

So, something like this:

Will result in:

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I hope this solves some problems, @FredrikEkstrom79, @lina-sbk-gbg!

BTW, it would be great if someone could add some documentation about this to the relevant place in our Wiki. Thanks!