Revert "[lldb] Make SBSection::GetSectionData call Section::GetSectionData."

This reverts commit 805600c7.

LLDB windows buildbots were broken by the TestSectionAPI.py test. I dont
have full context of the commit to fix it. Reverting it temporarily.

https://lab.llvm.org/buildbot/#/builders/83/builds/28617
https://lab.llvm.org/buildbot/#/builders/219/builds/180

Differential Revision: https://reviews.llvm.org/D142672