Design and prototype new collection browser

[michael-conway]

Collection browser is currently problematic (performance, limitations such as federation)

This is a space to start working on an upgrade that is

• faster
• incorporates saved searches and 'virtual collections'
• unifies browsing and search results
• displays data across federations
• uses paging that maps to iRODS pages and can page across query result sets seamlessly
• potentially can issue queries that span federated nodes and combines/caches search results

Cloud Browser can serve as a point of departure here, consider introducing a responsive framework for the browsing operation, Vue might be a lightweight alternative that can be utilized for this specific partition.

[michael-conway]

Would subsume #52, #22