Replaced PostgresRow:DatabaseRow with .databaseRow(using:) methods

Author: calebkleveter

Sources/PostgresKit/PostgresClient+SQL.swift

@@ -32,7 +32,7 @@ extension _PostgresSQLDatabase: SQLDatabase {
             return try self.database.query(sql, binds.map { encodable in
                 return try self.encoder.encode(encodable)
             }) { row in
-                onRow(row)
+                onRow(row.sqlRow(using: self.decoder))
             }
         } catch {
             return self.eventLoop.makeFailedFuture(error)

Sources/PostgresKit/PostgresRow+SQL.swift

@@ -1,6 +1,19 @@
-extension PostgresRow: SQLRow {
-    public func decode<D>(column: String, as type: D.Type) throws -> D where D : Decodable {
-        guard let data = self.column(column) else {
+extension PostgresRow {
+    public func sqlRow(using decoder: PostgresDecoder) -> SQLRow {
+        return _PostgreSQLRow(row: self, decoder: decoder)
+    }
+
+    public func sqlRow(using decoder: JSONDecoder = JSONDecoder()) -> SQLRow {
+        return _PostgreSQLRow(row: self, decoder: PostgresDataDecoder(jsonDecoder: decoder))
+    }
+}
+
+private struct _PostgreSQLRow: SQLRow {
+    let row: PostgresRow
+    let decoder: PostgresDecoder
+
+    func decode<D>(column: String, as type: D.Type) throws -> D where D : Decodable {
+        guard let data = self.row.column(column) else {
             fatalError()
         }
         return try self.decoder.decode(D.self, from: data)