Expose all flush-* operations to the datasource runtime view

Currently there's only one flush button which maps to :flush-gracefully-connection-in-pool(). Change the button to a drop down button which offers all flush operations available in WF 9.x

• flush-all-connection-in-pool
• flush-gracefully-connection-in-pool
• flush-idle-connection-in-pool
• flush-invalid-connection-in-pool

This applies to "Configuration / Datasources / Pool" and "Runtime / Datasources"