Add DialogSet.SetTelemetryClient(), and modify ComponentDialog

[daveta]

Incorporate Feedback from @Stevenic:

This enables ComponentDialog to set the TelemetryClient and updates all the underlying dialog's TelemetryClient

• Add DialogSet.TelemetryClient which will set the telemetryClient on all contained dialogs.
• Modify DialogSet.Add to set the TelemetryClient property on the dialog being added.
• Modify setter on ComponentDialog.TelemetryClient to set contained dialogs.
• Modify ComponentDialog.Add to set TelemetryClient property on the dialog being added.

[coveralls]

Pull Request Test Coverage Report for Build 44820

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 38 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.1%) to 55.687%

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Files with Coverage Reduction	New Missed Lines	%
/libraries/Microsoft.Bot.Builder.Dialogs/Dialog.cs	9	67.86%
/libraries/Microsoft.Bot.Builder.Dialogs/DialogSet.cs	10	77.55%
/libraries/Microsoft.Bot.Builder.Dialogs/ComponentDialog.cs	19	70.11%

Totals
Change from base Build 44745:	0.1%
Covered Lines:	5479
Relevant Lines:	9839

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💛 - Coveralls