Revert "WTS: Skip auto-inserted tags for empty nodes with 0-wide subtree DSR"

This reverts commit 7ecebc8ebd9b37d7ea905577ca1c66c6ee6b679b.

This is still unsafe in some edit scenarios -- where the
node's surrounding context changes. Reverting to figure out
if it is fixable at all. For later.

Change-Id: I099c7e369b4746f5e945720431dd873be86ad461
Merge "Revert "WTS: Skip auto-inserted tags for empty nodes with 0-wide subtree DSR""