Add column choices to Website Overview report

The website overview report does not allow for column selections so website downtime exports don't contain fields for monitor object properties/custom properties.

To enable more robust reporting, those additional fields (properties) are needed to visual data into appropriate segments.  Our executive team needs to be briefed on application level availability (web services) with breakdown of the data by client, product, business service, environment, supplier etc.  The monitor properties and custom fields we store in the services table provide the detail and should be made available for reporting.