[LiveMetrics] add support for collecting logs

[TimothyMothra]

Supersedes #42889
Follow up to #43081. (MUST wait for 43081 to merge before we can merge THIS pr)

This PR adds functionality to collect logs and send to LiveMetrics as TraceDocuments.

Changes

• Add new class LiveMetricsLogProcessor that collects OpenTelemetry LogRecord
• update LiveMetricsExtensions
  • signal specific extension methods are changed to private
  • new public extension method for OpenTelemetryBuilder. This depends on IServiceCollection to manage internal singletons.
• update Demo project
  • Until this project is rewritten as an AspNetCore application, had to manually setup a ServiceCollection

[rajkumar-rangaraj]

Can't we achieve this feature without this reference?

[TimothyMothra]

It could, but I don't think we want to.

This PR delivers a single extension method that configures LiveMetrics for both signals.
This extension method uses OpenTelemetryBuilder which comes from OpenTelemetry.Extensions.Hosting.

azure-sdk-for-net/sdk/monitor/Azure.Monitor.OpenTelemetry.LiveMetrics/src/LiveMetricsExtensions.cs

Line 30 in a11ec53

public static OpenTelemetryBuilder AddLiveMetrics(this OpenTelemetryBuilder builder, Action<LiveMetricsExporterOptions> configure = null)

Without this package, a user would need to configure our Manager singleton to the ServiceCollection and set LiveMetrics on both signals. I don't think we should take this approach.

Second, as we're preparing to shift our implementation to the Distro, it makes sense to take common dependencies now. This will make that shift easier.

[rajkumar-rangaraj]

The direction of this PR, which involves exposing a new API, is not the correct approach.

[TimothyMothra]

The direction of this PR, which involves exposing a new API, is not the correct approach.

We should sync offline, I think a new API is unavoidable until this code moves to the Distro project.

The way I see it we have two options. For context, as of today we have one public extension method for TracerProviderBuilder.

1. Replace the current method with a single extension method for OpenTelemetryBuilder that configures LiveMetrics for both Traces and Logs.
2. Add a second extension method for OpenTelemetryLoggerOptions.

Without either of these, our Distro project cannot setup LiveMetrics.

[rajkumar-rangaraj]

The direction of this PR, which involves exposing a new API, is not the correct approach.

We should sync offline, I think a new API is unavoidable until this code moves to the Distro project.

The way I see it we have two options. For context, as of today we have one public extension method for TracerProviderBuilder.

1. Replace the current method with a single extension method for OpenTelemetryBuilder that configures LiveMetrics for both Traces and Logs.
2. Add a second extension method for OpenTelemetryLoggerOptions.

Without either of these, our Distro project cannot setup LiveMetrics.

I'm working on this foundation, will send a PR shortly.