Feature: DB Integration: Azure Cosmos DB

[RohanNagar]

Description:

We can allow for different database providers in Thunder. There should be an ability to specify which DB provider is desired in the config, and then Thunder will use the correct implementation. We need to also implement Cosmos DB.

Additional Information:

https://docs.microsoft.com/en-us/azure/cosmos-db/

https://github.com/zeit/cosmosdb-server

https://docs.microsoft.com/en-us/java/api/overview/azure/cosmos-readme?view=azure-java-stable