Improve stream interface compatibility by adding pause/resume

[dhensby]

What this does:

• Adds pause/resume methods to request objects

How:

• Store the current tedious request object by reference
• pass through the pause / resume calls

Related:

• Stream is not a true node stream #161
• Implements Request.pause() / resume() tedious#518 (comment)

Issues:

• SQL Server v8 driver doesn't appear to expose resume / pause functionality.

[dhensby]

Testing locally pausing and resuming works as expected 🎉

[dhensby]

Right, having looked into "true node streams" I don't think the effort is fully justified right now and especially without an RFC and some major changes to this lib. Possibly in v6 or v5 if we can justify pushing the alpha phase for a long while...

For now I'm going to look into writing a test for this, but I'm not sure how valuable that is as we are 100% dependant on tedious adhering to the pause/resume contract.

[dhensby]

Right, I'm going to be rude and merge this without tests because this is purely a passthrough to tedious and any integration test would be silly and I can't see a nice way to unit test this right now... :(