If a resource's options bag does not specify `protect` or `provider`,
pull a default value from the resource's parent.
In order to allow a parent resource to specify providers for multiple
resource types, component resources now accept an optional map from
package name to provider instance. When a custom resource needs a
default provider from its parent, it checks its parent provider bag for
an entry under its package. If a component resource does not have a
provider bag, its pulls a default from its parent.
These changes also add a `parent` field to `InvokeOptions` s.t. calls to
invoke can use the same behavior as resource creation w.r.t. providers.
Fixes#1735, #1736.
58a75cbbf4