getRecords metadata

[khaliqgant]

Introduce a new parameter for getRecords: include_nango_metadata=true

If true, this wraps the returned records in a Nango metadata object, where we add additional details about the record:

{
	"first_seen_at": "timestamp",
	"last_modified_at": "timestamp",
	"last_action": "ADDED", // or MODIFIED, in future also DELETED
	"record": {
		// user defined record
	}
}