ComprehendFullAccessPolicy Is Needed

**Description:**

SAM, defining function within YAML. Function calls async Comprehend capabilities (classic start/complete). ComprehendBasicAccessPolicy does not include the basic async calls and seems limited to async calls. We either need to expand ComprehendBasicAccessPolicy to include async calls or, alternately, create a full access policy for comprehend. In reality, perhaps both are best. As such, we'd also need passrole for async.