Look for tsr only on start-elem when collecting tpl ranges.

* findWrappableTemplateRanges was only looking for tpls that had
  valid tsr set.  However, it was testing both start and end tags.
  But, in the presence of wikitext errors, the end-tag may not
  have a valid tsr even if the start tag did.  This led to some
  top-level tpl ranges not getting wrapped.

  Ex: <ref>{{echo|bar}}<!--bad-></ref>

* Fixed the check to only look for tsr on the start-tag, not the
  end tag.

* This fixes the RT-ing of the snippet above as well as on other
  pages like: en:Turkish Yeni Lira

* No change in parser tests (TODO: Add variant of above)

Change-Id: I183c7c7065d784b8a52cf2bf66c3a519c35fd136