[Assets] Add Assets class (#1528)

* Created Assets() class, heavily copied from Insight(). Changed references from Insight to Assets where appropriate. Removed deprecated functions. Replaced iql() with aql() [cloud-only] and navlist_aql() [server-only].

* Created Assets() class, heavily copied from Insight(). Changed references from Insight to Assets where appropriate. Removed deprecated functions. Replaced iql() with aql() [cloud-only] and navlist_aql() [server-only].

* Removed import deprecated

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Co-authored-by: Andrew Culver <aculver@uwo.ca>