ticket:10046: Introduce ScientificFormatHelper class.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@35612 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10046: Attempt to fix broken build.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@35613 251d0590-4201-4cf1-90de-194747b24ca1