[Twilio Adapter] Replace interfaces with classes

[ceciliaavila]

Proposed Changes

Replace interfaces with classes to allow versioning.

Detailed changes

• Remove ITwilioClient interface.
• Convert interface ITwilioAdapterOptions into a class
• Rename TwilioApi class as TwilioClientWrapper and make its methods virtual.
• Adjust TwilioAdapter class and unit tests to these changes.
• Replace explicit types with var

[coveralls]

Pull Request Test Coverage Report for Build 77499

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 350 unchanged lines in 52 files lost coverage.
• Overall coverage decreased (-1.8%) to 78.496%

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Files with Coverage Reduction	New Missed Lines	%
/libraries/integration/Microsoft.Bot.Builder.Integration.ApplicationInsights.Core/ApplicationBuilderExtensions.cs	1	71.43%
/libraries/Microsoft.Bot.Builder.AI.LUIS/LuisApplication.cs	1	95.45%
/libraries/Microsoft.Bot.Builder.Dialogs/Prompts/PromptValidatorContext.cs	1	82.35%
/libraries/Microsoft.Bot.Builder.Dialogs/WaterfallStepContext.cs	1	86.96%
/libraries/Microsoft.Bot.Builder/TelemetryLoggerMiddleware.cs	1	57.58%
/libraries/Microsoft.Bot.Builder.Testing/XUnit/TestDataObject.cs	1	82.35%
/libraries/integration/Microsoft.Bot.Builder.Integration.AspNet.Core/HttpHelper.cs	2	90.91%
/libraries/integration/Microsoft.Bot.Builder.Integration.AspNet.Core/ServiceCollectionExtensions.cs	2	94.94%
/libraries/Microsoft.Bot.Builder/ActivityHandler.cs	2	8.33%
/libraries/Microsoft.Bot.Builder.AI.LUIS/Generator/DateTimeSpec.cs	2	64.29%

Totals
Change from base Build 77218:	-1.8%
Covered Lines:	4300
Relevant Lines:	5478

---

💛 - Coveralls

[fuselabs]

✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.Luis.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.QnA.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.ApplicationInsights.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Azure.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Dialogs.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.TemplateManager.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Configuration.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Connector.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Schema.dll compared against version 4.3.1

[fuselabs]

✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.Luis.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.QnA.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.ApplicationInsights.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Azure.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Dialogs.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.TemplateManager.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Configuration.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Connector.dll compared against version 4.3.1
✔️ No Binary Compatibility issues for Microsoft.Bot.Schema.dll compared against version 4.3.1

[gabog]

looks good to me, I think it can be merged. thanks!