Measurement level 2 hex

[DanPuzzuoli]

PR #373 converted the meas level 2 results to be returned in hexadecimal. This has resulted in tests failing:

• Some are simply that the checks are done on binary strings, which is easy to fix, but:
• Others are due to the fact that the DynamicsBakend has the option to return measurements of higher energy states, resulting in non-binary result strings, which fail in the conversion (which assumes base 2).

Some solutions:

• Add the option to return results in the original bit strings
• Disable measurement of higher level energy states (I think not preferred)

For now I'm going to leave this for general discussions about pulse migration.