report: check report type and options used for full report's subreports
If we have fullreport, make sure that the options/sort keys used for
each report doesn't change its type - we want to preserve the original
type so it's always 5 different subreports within fullreport (vg, lv, pv,
seg, pvseg). Since we have all report types within fullreport, users
should add fields under proper subreport type - this minimizes
duplication of info displayed on output.