Add durations of pulse gates from DAG calibrations

[nbronn]

Summary

The scheduling passes of the transpiler need to be informed of the durations of the gates. In the case of pulse gates, these durations need to be added from dag.calibrations to the node.op. The following PR fixes this by checking to see if a calibration exists in dag.calibrations for node.op.name and if so adds node.op.duration from it.

Details and comments

Ideally I would have used dag.has_calibration_for(node) to check for the existence of a calibration, but found the method did not always work. Perhaps I will raise this in a separate issue.

This additionally fixes an issue where a bound ParameterExpression is passed to a calibration builder by casting it to a float.

[coveralls]

Pull Request Test Coverage Report for Build 1731452580

• 6 of 11 (54.55%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.005%) to 83.145%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/transpiler/passes/scheduling/alap.py	3	4	75.0%
qiskit/transpiler/passes/scheduling/asap.py	0	4	0.0%

Totals
Change from base Build 1731292000:	-0.005%
Covered Lines:	52005
Relevant Lines:	62547

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💛 - Coveralls