Update to ICU 70.1

Update to ICU 70.1

Unicode 14, 5 new scripts, 12 new Unicode blocks.

In i18npool/qa/cppunit/test_breakiterator.cxx
TestBreakIterator::testLao() had to be disabled/adapted.
Needs to be investigated, see comments there.
As is, Lao script word break has regressions.

Correct UBLOCK_TANGUT_SUPPLEMENT Unicode range endpoint to
0x18D7F, see
https://www.unicode.org/versions/Unicode14.0.0/erratafixed.html
for which ublock_getCode(0x18D8F) now returned UBLOCK_NO_BLOCK and
thus luckily the assert in svx/source/dialog/charmap.cxx hit.

Change-Id: I4bad16ecfab3f44be365b8f884c57f34af68218e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/125322
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins
Gbp-Pq: Name icu-70.diff