(PUP-1515) Autoload types and providers from same environment

Prior to this patch, Types were autoloaded from the environment specified by
the agent node while providers were autoloaded from the master's "default"
environment. This caused Types to sometimes be loaded without providers wich in
turn caused catalog compilation to fail during validation with "Invalid
parameter provider".
Merge pull request #2963 from Sharpie/pup-1515-spike-provider-autoloading

(PUP-1515) Spike patch for autoloading providers