Handle large numbers of vocabularies

[rob-metalinkage]

Its not clear how the new build will handle this without an example and there is no information on the description page about the scope and capabilities.

The obvious limitation of VocPrez is that large lists of vocabularies on the index page became useless and irritating - there needs to be a way of grouping families of vocabularies and lazy-loading on explicit expansion (without compromising search!)

For example, a real application schema may have many vocabularies defined as codelists -e.g. http://defs.opengis.net/vocprez/vocab/

check out "Pipeline-ML" - >100 codelists completely wrecks this view.

Annotating Concept Schemes with some classification might work - but this would need to be configurable in the UI - probably supporting an ordered whitelist of classifications.

Possibly a pre-load whitelist might be useful for the balance between first-look and performance scaling too.

AFAICT the average number of vocabularies for an observations based system would be about 30 - but this may be conservative if there is much heterogeneity in the observation sensors.