feat(error exposure): Integrated onError() callback in TransmissionPr…

[rastogitech]

• Errors can occur while sending data on Azure Application Insight servers.
• Right now, Logger class reports the error details but doesn't tell the telemetry details. Also, the error detail isn't reported in its true reported form.
• SDK must expose a way to let the client application know about the error along with their associated telemetry details.
• onError() callback is introduced in TransmissionProcess to provide this capability.

[rastogitech]

Dear @mernen @kentcb @robsonsilv4 @RCSandberg, please review this pull request as we need this feature a must in this SDK.

Test edit

[avinyapotter]

Hi @kentcb, checking out with you if we can have this pull request changes in the SDK.

[rastogitech]

Hi @kentcb, can have this pull request changes in the SDK.

[rrastogi-ex2]

Any update on this?