Add support for dialects

[breezykermo]

There is notionally the option in a Blueprint to support one or more 'dialects', each of which represents a query language: that is, a mode in which its tabs and resources are available for consumption.

Currently, each Blueprint defaults to presenting information in a REST-like format. Each resource is available in full at /source/tab/resource, or its elements individually at api/source/tab/resource/id.

The query language should be relegated to a 'rest' dialect (where dialects are specified in each Blueprint). This would allow for the presentation of source information in other query languages, such as GraphQL or custom query languages as well.