DELAY accepts frames with no qubits

[mhodson-rigetti]

Pre-Report Checklist

• [x] I am running the latest versions of pyQuil and the Forest SDK
• [x] I checked to make sure that this bug has not already been reported

Issue Description

The following pyquil program parses successfully, but is not IAW the Quil specification section 12.7 which says DELAY must have at least one qubit identifier.

program = Program("""
DELAY "FrameA" "FrameB" "FrameC" 2.48e-7
""")

Environment Context

pyquil==4.10.1