Use CorrelationId to track Sub-LSP call duration for Diagnostics

[maryamariyan]

Summary of the changes

• Includes a correlation ID, a Guid we generate for the sub LSP call to help correlate between the calls that are for the same main Diagnostics LSP request (As with diagnostics we may send sub LSP call for both html and C# LSP server and this way we can associate them together using this id).

/cc @ryzngard @davidwengier

Related to #8539

[maryamariyan]

I'm looking at adding tests too. But existing feedbacks seem addressed and the functionality seems to be working fine

Note: Ignore the actual ms timing because this was done in debug mode and hence not the best representation, but the ratios are probably more meaningful.

- TelemetryReporter.TelemetryScope.Dispose(): Took 165ms with correlationId {a993e40f-d6a3-4854-a0a7-fcca28c518c8} with "HtmlDelegationLanguageServerClient" during "textdocument/_vs_diagnostic"
- TelemetryReporter.TelemetryScope.Dispose(): Took 1585ms with correlationId {a993e40f-d6a3-4854-a0a7-fcca28c518c8} with "Razor C# Language Server Client" during "textdocument/_vs_diagnostic"
- TelemetryReporter.TelemetryScope.Dispose(): Took 2076ms with correlationId {a993e40f-d6a3-4854-a0a7-fcca28c518c8} with "Razor Language Server Client" during "textdocument/_vs_diagnostic"

[DustinCampbell]

Looks good to me! Thanks for considering all of the feedback.

[maryamariyan]

Filed #8801 to track the need for integration testing to verify the telemetry events are fired when expected.

I tested manually and they work as expected, merging.