Use combined all field for near_match

This is less important then the combined all fields for plain and text
matching, but it is still helpful.

Also, fix some issues with fuzzy queries using the all fields and with
the opening weighting using the all fields.  It was 8 which made opening
text 10 (8 for opening + 2 for text) which was too high compared to headings.
Lowered it to 6.

Bug: 68167
Change-Id: Id561b44e6461bb4719a9ee42350d80619fbdbc85
Merge "Use combined all field for near_match"