Changing columns WITH/WITHOUT SYSTEM VERSIONING doens't require to read data at
all. Thus it should be an instant operation.
Patch also fixes a bug when ALTER_COLUMN_UNVERSIONED wasn't passed to InnoDB
to change its internal structures.
change_field_versioning_try(): apply WITH/WITHOUT SYSTEM VERSIONING
change in SYS_COLUMNS for one field.
change_fields_versioning_try(): apply WITH/WITHOUT SYSTEM VERSIONING
change in SYS_COLUMNS for every changed field in a table.
change_fields_versioning_cache(): update cache for versioning property
of columns.
9dc81f7d38