SqlQuery enhance Result Type output

### Problem Overview
When using the Elsa.Sql module's SqlQuery activity, the result is returned as a DataSet. This is not the easiest result type to handle, especially if using expressions or Javascript / C# to manipulate the result within a workflow.

### Proposed Solution
Provide ResultType input parameter (default to DataSet) that provides a Dropdown selection from registered handlers to support different output result types. eg: Array of objects (Dictionary[]) Handlers can be custom defined or usage of predefine handler as part of the Elsa.Sql module.

### Use Cases
If you need to manipulate data returned from a SqlQuery activity within a workflow... by using "RecordSet" result type, will provide output as an array of objects. Javascript can then use {data}.find(...) or .filter(...) functions to query and manipulate the data returned from the SqlQuery in a much easier way.