report: also display "mirror" keyword in lv_type for pvmove LV and display "multiple...

report: also display "mirror" keyword in lv_type for pvmove LV and display "multiple" for external origin used for more than one thin snapshot

$ lvs -a -o name,vg_name,attr,layout,type
  LV        VG     Attr       Layout     Type
  lvol0     vg     -wI-a----- linear     linear
  [pvmove0] vg     p-C-aom--- mirror     mirror,pvmove

(added "mirror" for pvmove LV)

$ lvs -a -o name,vg_name,attr,layout,type
  LV              VG     Attr       Layout     Type
  lvol0           vg     ori------- linear     external,multiple,origin,thin
  [lvol1_pmspare] vg     ewi------- linear     metadata,pool,spare
  lvol2           vg     Vwi-a-tz-- thin       snapshot,thin
  lvol3           vg     Vwi-a-tz-- thin       snapshot,thin
  pool            vg     twi-a-tz-- pool,thin  pool,thin
  [pool_tdata]    vg     Twi-ao---- linear     data,pool,thin
  [pool_tmeta]    vg     ewi-ao---- linear     metadata,pool,thin

(added "multiple" for external origin used for more than one
thin snapshot - lvol0 in the example above)