View indexing is very slow, due to mis-optimized SQLite query

[djpongh]

From: couchbase/couchbase-lite-ios#1737

Using EXPLAIN QUERY PLAN I found that the optimizer has generated a horrifically bad plan, essentially an inside-out join, that results in linear scans of two large tables. (Presumably this is due to some change in the optimizer between the older and newer versions of SQLite in iOS.)