Support "mapped" flag for StudioOpenDialog in isfs filters and export

[isc-tleavitt]

Use case:
I want to connect to an interoperability-enabled namespace using isfs, and to export everything from it to my local filesystem. I don't want InterSystems' code to be included - e.g., the CSPX, Ens*, HS*, and SchemaMap packages. The defining characteristic of these is that they are mapped from non-default routine DBs for the namespace.

Fortunately, %Library.RoutineMgr:StudioOpenDialog has a "Mapped" option which defaults to 1 but can be set to 0 to omit these classes. We should support "mapped=false" as a URL parameter and export config option to support omitting mapped classes from both isfs views and export. (This could be two separate issues, but I think it makes more sense as a single issue to support a systemic review of all places where this flag might be relevant.)