Updated gap_mark importing for chinese documents:

* added validation `gap_marks_count_match`
* run `fix_adjust_gap_mark_positions` on gap_mark_tagging_import file
* don't validate gap_marks in invalid positions for chinese files since they have no word boundaries
* updated `fix_adjust_gap_mark_positions` to properly handle chinese documents
Updated PDF export for recording_merged:

* added special characters to skip for highlighting the word after a gap_mark
* drop id_title1 and id_title2
* move id_paragraph to beginning of document
* improve reporting on gap_mark_counts match validation