Temporary fix for bug 47954 - keep section link in edit summary

Since talk page edits don't necessary belong to a seciton (or may
involve several sections), we'll need to be more clever in the
DiscussionParser to extract it for the long term solution. This
temporary solution will expose any section link in the edit summary
payload so that people can jump straight to the section if they
want to (same as existing behavior in the archive version).

Bug: 47954
Change-Id: I2745ba194ba1f9b5b7c446588da6586e87d35b31
Merge "Temporary fix for bug 47954 - keep section link in edit summary"