Feature Request - SQL Server - WriteMode

[gpltaylor]

I would like to be able to update/insert/delete using the SQL Server extention.

Supporting a option called WriteMode, I would like to be able to upsert data into SQL Server.

Example

  "SinkSettings": 
  {
    "ConnectionString": "<sql connection String>",
    "Database": "PaymentService",
    "TableName": "AccountTransactions",
    "BatchSize": 1000,
    "WriteMode": "upsert",
    "ColumnMappings": [
      {
        "ColumnName": "Id",
        "SourceFieldName": "Id"
      }
    ]
  }