Search/Query Index APIs don't use the default management timeout

Motivation
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• The Index Manager APIs don't use the default Management Timeout (75s).
• The Index Manager APIs' options only expose a "CancellationToken" in the options, which defaults to "CancellationTokenCls.None".

Desired Resolution
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• Expose both a CancellationToken and Timeout method in the options, which both fill a single CancellationToken backing field.
• Have that backing field default to a CancellationToken issued from a CTS with the default Management Timeout (See the behaviour for Bucket and Collection managers' options).