Create FunctionConfig for Lake-of-Segments and move "static" info to it.

[mscaldas2012]

For performance purposes, our AZ Functions are set to be Always ON.
Because of that, we can initiate and cache some things at the class level so that we don't have to perform those operations every time the FN is invoked.

Create a FunctionConfig class that initializes environment variables and static config files.
Instantiate the FunctionConfig at the class level on the AZ Function class.

For Lake of Segments FN:

• Move Reading Environment variables to Function Config.
• Move eventHubSender to FunctionConfig
• Load BasicProfile config on TransformerSegment init (and cache it in-memory)
• Move TransformerSegment to FunctionConfig and init it there.

Other refactoring:

• Move val startTime = Date().toIsoString() to inside the messages.forEach loop
• Enhance Logging (See Receiver/Debatcher for template)
  • prefix every logging with "DEX::
  • Log receiving message, sending message and any error (catches should have a logging)
  • Do not include entire message on logs (PII issues). Keep logs short.

[guntukuhari]

PR - #1051