At some places in the docs, we refer to them as tablesync slots and at other
places as table synchronization slots. For consistency, we refer to them as
table synchronization slots at all places.

Author: Peter Smith
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CAHut+PvzYNKCeZ=kKBDkh3dw-r=2D3fk=nNc9SXSW=CZGk69xg@mail.gmail.com