.Net: Refactor AssemblyAI connector to use AssemblyAI SDK

[Swimburger]

Motivation and Context

Description

By using the SDK, users can use the TranscriptOptionalParams class from the SDK to pass parameters to the AssemblyAI transcription endpoint.

Contribution Checklist

• [x] The code builds clean without any errors or warnings
• [x] The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• [x] All unit tests pass, and I have added new tests where possible
• [x] I didn't break anyone :smile:

[rogerbarreto]

Fix small format issues.

[Swimburger]

Hi folks, any more changes needed here?

[Swimburger]

@RogerBarreto Sounds like everything is good to move forward. Once this is merged in, I can work on implementing real-time STT

[rogerbarreto]

Please fix all format issues

Run dotnet build -c Release for building the solution, this will trigger any formating issue before pushing

[Swimburger]

@RogerBarreto looks like all checks are passing now

[rogerbarreto]

@Swimburger, the pipeline is breaking, mind having a look 😊

[Swimburger]

@RogerBarreto Thank you for taking care of this. I don't work for AssemblyAI anymore, but I'd be happy to continue to drive this.