Allow more than 4 sales tax names to be added to a

Allow more than 4 sales tax names to be added to a sales tax code

Currently, in Los Angeles, there are up to 5 types of sales tax that could be collected for any address. In order to properly account for this, we have to create combined tax types and then maintain records for end of period distributions. I've attached an image of a rate breakdown for an address in Campbell, CA.