Issue #2117

Port existing ProcessSmsQueueMessage and ProcessEmailQueueMessage WebJobs to Azure Functions.

Consistency with the existing WebJobs has mostly been retained except for the following changes:

• Storage account application setting changed to AzureWebJobsStorage from Data:Storage:AzureStorage as this is the default setting for Function Apps
• Use Twilio output binding instead of REST client
  ref: https://www.nuget.org/packages/Microsoft.Azure.WebJobs.Extensions.Twilio/1.0.0
• Use SendGrid output binding instead of Web transport
  ref: https://www.nuget.org/packages/Microsoft.Azure.WebJobs.Extensions.SendGrid/2.0.0
• Sendgrid NuGet package updated to 8.0.5 as required by Microsoft.Azure.WebJobs.Extensions.SendGrid. Note: Sendgrid version 9.0.0 is not supported by Microsoft.Azure.WebJobs.Extensions.SendGrid version 2.0
• As a side effect of using the SendGrid output binding, the output mail message is constructed using the SendGrid.Helpers.Mail.Mail class instead of SendGrid.SendGridMessage
• Another side effect of using the SendGrid output binding is that authentication must be done using an API key instead of username/password. A new application setting Authentication:SendGrid:ApiKey has been added to accommodate this.