support multiple location types simultaneously

[graybeal]

Is your feature request related to a problem? If so please describe.
Some users will want any data that is relevant, no matter the location type. Some will want data only for certain location types (but more than one).

Describe the solution you'd like
A clear and concise description of what you want to happen.
Allow users to specify areas using either location items of a particular type, or via a map selection, but is capable of finding and returning data in that area that is indexed by other location types (either all other types, or selected other types). This option would be a configuration setting, and would likely need sub-settings to control whether other data locations have to be wholly within the chosen area or can be overlapping it.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

• Merging data of different location types into a common location type is another (even harder) task (transform (crosswalk) data into common location type #29).
• Use ACS Fact Finder style interface to let you navigate to the regions you want to specify [Mathew]

Additional context
Add any other context or screenshots about the feature request here.
This is a key contribution to making the whole experience frictionless.