Add a "Map Explorer" to query builder

[maxpatiiuk]

Is your feature request related to a problem? Please describe.
The Map Explorer feature in the Workbench Mapping Editor is very useful.

Describe the solution you'd like
It would be nice to add something similar to the query builder

Reported By @acbentley

[maxpatiiuk]

Fixed in 2df24e9

[grantfitzsimmons]

This is so amazing. Just wanted to add a comment mentioning how exciting this feature is.