Report input/output latency

[SolarLiner]

Problem Statement

In order to give users the ability to do full latency compensation, it is crucial that we give them the reported input/output latencies, if provided by the driver.

This is especially important with #22 that will bring its own latency when resampling.

Proposed Solution

Add a latency: Option<Timestamp> to AudioInput and AudioOutput exposing the reported latency information

Alternative Solutions

• Not reporting latency: having the information could be misleading as an accurate measurement, which I don't think it is on most platforms unless using pro audio with correct latency measurements.
• Reporting latency another way (how?)

Checklist

• I have searched for existing issues that may be similar
• I have explained the feature's value proposition
• I have provided concrete examples (not done; hopefully self-explanatory)