Allow manual invalidation of a resource given a method and URI

This covers a use case whereby you send a request to an endpoint that will affect multiple resources, but the affected resources cannot be identified by the URI or provided through linked patterns. It also caters for invalidating resources on completion of long running operations that may be out of process.

For example, POST to /Api/Data/Tags, with content:

{
  Added: ["Best Practice"],
  DataIds: { "ABC123", "DEF456" }
}

Need to invalidate /Api/Data/ABC123, /Api/Data/DEF456 so this has to be done manually.