Store AddParaLineSpacingToTableCells in configuration as
"AddTableLineSpacing", consistently inconsistent like AddTableSpacing
(the <desc> elements are not subject to translation).
Adapt SwCompatibilityOptPage with some ugly hacks to allow 3 different
states (TriState) for the corresponding checkbox that map to false/false,
true/false and true/true.
The checkbox widget doesn't allow to change *to* indeterminate but at
least the status of the document can be displayed this way,
with a non-obvious tweak to optcompatpage.ui to reference "checktri1"
column.
Change-Id: I5f32e05c93b5e16e782cba5d1d055809d9e5e251
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/103318
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@cib.de>
