Repeating table headers consisted of more than 10 table rows
switch off table header repetition during DOCX table import
to fix non-visible table content and broken tables.

Repeating header lines are not visible in MSO, if there is no space for them.
OOXML (and ODF) standards don't specify this exception, and unfortunately,
it's easy to create tables with invisible repeating headers in MSO, resulting
OOXML files with non-standardized layout. To show the same or a similar layout
in LibreOffice (instead of a broken table with invisible content), we use a
reasonable 10-row limit to apply header repetition, as a workaround.
Later it's still possible to switch on header repetition or create a
better compatible repeating table header in Writer for (pretty unlikely) tables
with really repeating headers consisted of more than 10 table rows.

Note: This workaround could help to create standard and more portable OOXML
files in a mixed environment.

Change-Id: I17fbc0173ec1c4f188a46227b99dde5726530da3
Reviewed-on: https://gerrit.libreoffice.org/60689
Tested-by: Jenkins
Reviewed-by: László Németh <nemeth@numbertext.org>