Revisit LogInformation statements

[singhk97]

Motivation

We expect developers to have LogInformation statements (and hence greater log levels) enabled in production. And so it should provide just enough information to be achieve the following goals:

• Be able to identify the issues by tracing logs through internal activity processing pipeline.
• Get suggestions when incomming activity is not handled.
• Have access to metadata that helps us, as SDK owners, with debugging.
• No PIIs should be logged.
• Logs shouldn't be too verbose or contain redundant information.

Changes

• Removed BeginScope since it will add the passed context to every log statement, forcing the developer to manually configure filtering in their logging infrastructure.
• On BotApplication.ProcessAsync add logging of the MSCV & ServiceUrl.