Identify how DAB is hosted for connections to MYSQL

[abhishekkumams]

• Adding useragent to cosmos client #1486 Added an environment variable to identify how DAB was hosted for CosmosDB.
• Adding application Name for mssql connections #1620 Adding application Name for MsSql connections.
• This issue is to do something similar for MYSQL by setting the Application Name for example prefixed with DAB_OSS or DAB_Hosted.