Create a single TBODY element for each block of rows
Create a single TBODY element for each block of rows

Improves the fix_table method, which was previously creating unnecessary TBODY elements around every single TR

Closes #1340
BrunoDeBarros/dompdf,nathanntg/dompdf,dompdf/dompdf,nathanntg/dompdf,BrunoDeBarros/dompdf,dompdf/dompdf