R1:7c3cb5948c2e

Drydock blueprint for preallocated remote hosts

Summary:
This adds a Drydock blueprint for preallocated, remote hosts. This will be used by the Harbormaster interface to allow users to specify remote hosts that builds can be run on.

This adds a `canAllocateResource` method to Drydock blueprints; it is used to detect whether a blueprint can allocate a resource for the given type and attributes.

Test Plan:
Ran:

```
bin/drydock lease --type host --attributes remote=true,preallocated=true,host=192.168.56.