New contribution receipt settings

We've added a number of new settings to make contribution receipts more accurate.

First, since some churches have a different legal name than the name they go by, there is a new "legal name" option on the church settings page. When generating receipts, the legal name will be preferred over the regular name.

Similarly, there is now new "mailing address" option on the church settings page, as churches often have a different mailing address than their worship address. The mailing address will be preferred over the worship address when generating receipts.

Finally, there is a new "authorized name" option on the giving settings page, which allows you to set the name associated with the authorized signature. This name will be shown with the authorized signature when generating receipts.