Put abbreviation logic into puttuple_common()
Abbreviation code is very similar along tuplesort_put*() functions. This
commit unifies that code and puts it into puttuple_common(). tuplesort_put*()
functions differs in the abbreviation condition, so it has been added as an
argument to the puttuple_common() function.
Discussion: https://postgr.es/m/CAPpHfdvjix0Ahx-H3Jp1M2R%2B_74P-zKnGGygx4OWr%3DbUQ8BNdw%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Pavel Borisov, Maxim Orlov, Matthias van de Meent
Reviewed-by: Andres Freund, John Naylor