always logged properly with binlog_row_image=MINIMAL

There are two issues fixed in this commit.
The first is an observation of a multi-table UPDATE binlogged
in row-format in binlog_row_image=MINIMAL mode. While the UPDATE aims
at a table with an ON-UPDATE attribute its binlog after-image misses
to record also installed default value.
The reason for that turns out missed marking of default-capable fields
in TABLE::write_set.

This is fixed to mark such fields similarly to 10.2's MDEV-10134 patch (db7edfed)
that introduced it. The marking follows up 93d1e5ce's idea
to exploit TABLE:rpl_write_set introduced there though,
and thus does not mess (in 10.1) with the actual MDEV-10134 agenda.
The patch makes formerly arg-less TABLE::mark_default_fields_for_write()
to accept an argument which would be TABLE:rpl_write_set.

The 2nd issue is extra columns in in binlog_row_image=MINIMAL before-image
while merely a packed primary key is enough. The test main.mysqlbinlog_row_minimal
always had a wrong result recorded.
This is fixed to invoke a function that intended for read_set
possible filtering and which is called (supposed to) in all type of MDL, UPDATE
including; the test results have gotten corrected.

At *merging* from 10.1->10.2 the 1st "main" part of the patch is unnecessary
since the bug is not observed in 10.2, so only hunks from

  sql/sql_class.cc

are required.