Add support for configurable PDF page and labels formats

Add support for configurable PDF page and mailing label formats. Page format configuration includes paper size, orientation, and margins. Mailing label format configuration includes paper size, orientation, margins, label dimensions and layout, and font styles. Selectable paper sizes include all standard US and ISO sizes, including envelope sizes. Default page and label formats can be configured and new formats can be created to choose from.

Message templates can be configured to specify a corresponding page format to use when creating PDF letters. Workflow templates can also be configured to specify a page format to use when the template is used to create a PDF email attachment. The default page format will be used when no format is configured.