Improved the PDF export output

CRM/DataprocessorOutputExport/PDF.php

docs/CustomizePdfTemplate.md

.../CRM/DataprocessorOutputExport/Form/Configuration/PDF.tpl

templates/CRM/DataprocessorOutputExport/PDF/Default/html.tpl

templates/CRM/DataprocessorOutputExport/PDF/Default/row.tpl

...lates/CRM/DataprocessorOutputExport/PDF/Default/table.tpl

.../DataprocessorOutputExport/PDF/DefaultFullBorder/html.tpl

...M/DataprocessorOutputExport/PDF/DefaultFullBorder/row.tpl

...DataprocessorOutputExport/PDF/DefaultFullBorder/table.tpl

...DataprocessorOutputExport/PDF/DefaultFullBorder/title.txt

...RM/DataprocessorOutputExport/PDF/DefaultNoBorder/html.tpl

...CRM/DataprocessorOutputExport/PDF/DefaultNoBorder/row.tpl

...M/DataprocessorOutputExport/PDF/DefaultNoBorder/table.tpl

...M/DataprocessorOutputExport/PDF/DefaultNoBorder/title.txt

templates/CRM/DataprocessorOutputExport/PDF/README.md