Add support for uuidRepresentation and journal to the connection string

As part of the standardization of the connection string format there are some differences with the current C# driver connection string format:

uuidRepresentation is the name in the standard connection string for the current guids option
journal is the name in the standard connection string for the current j option

Change the connection string parsing code to use the new names, while still recognizing the old ones for backward compatibility reasons.