Add lv_layout_and_type fn, lv_layout and lv_type reporting fields.

Add lv_layout_and_type fn, lv_layout and lv_type reporting fields.

The lv_layout and lv_type fields together help with LV identification.
We can do basic identification using the lv_attr field which provides
 very condensed view. In contrast to that, the new lv_layout and lv_type
fields provide more detialed information on exact layout and type used
for LVs.

For top-level LVs which are pure types not combined with any
other LV types, the lv_layout value is equal to lv_type value.

For non-top-level LVs which may be combined with other types,
the lv_layout describes the underlying layout used, while the
lv_type describes the use/type/usage of the LV.

These two new fields are both string lists so selection (-S/--select)
criteria can be defined using the list operators easily:
  [] for strict matching
  {} for subset matching.

For example, let's consider this:

$ lvs -a -o name,vg_name,lv_attr,layout,type
  LV                    VG     Attr       Layout       Type
  [lvol1_pmspare]       vg     ewi------- linear       metadata,pool,spare
  pool                  vg     twi-a-tz-- pool,thin    pool,thin
  [pool_tdata]          vg     rwi-aor--- level10,raid data,pool,thin
  [pool_tdata_rimage_0] vg     iwi-aor--- linear       image,raid
  [pool_tdata_rimage_1] vg     iwi-aor--- linear       image,raid
  [pool_tdata_rimage_2] vg     iwi-aor--- linear       image,raid
  [pool_tdata_rimage_3] vg     iwi-aor--- linear       image,raid
  [pool_tdata_rmeta_0]  vg     ewi-aor--- linear       metadata,raid
  [pool_tdata_rmeta_1]  vg     ewi-aor--- linear       metadata,raid
  [pool_tdata_rmeta_2]  vg     ewi-aor--- linear       metadata,raid
  [pool_tdata_rmeta_3]  vg     ewi-aor--- linear       metadata,raid
  [pool_tmeta]          vg     ewi-aor--- level1,raid  metadata,pool,thin
  [pool_tmeta_rimage_0] vg     iwi-aor--- linear       image,raid
  [pool_tmeta_rimage_1] vg     iwi-aor--- linear       image,raid
  [pool_tmeta_rmeta_0]  vg     ewi-aor--- linear       metadata,raid
  [pool_tmeta_rmeta_1]  vg     ewi-aor--- linear       metadata,raid
  thin_snap1            vg     Vwi---tz-k thin         snapshot,thin
  thin_snap2            vg     Vwi---tz-k thin         snapshot,thin
  thin_vol1             vg     Vwi-a-tz-- thin         thin
  thin_vol2             vg     Vwi-a-tz-- thin         multiple,origin,thin

Which is a situation with thin pool, thin volumes and thin snapshots.
We can see internal 'pool_tdata' volume that makes up thin pool has
actually a level10 raid layout and the internal 'pool_tmeta' has
level1 raid layout. Also, we can see that 'thin_snap1' and 'thin_snap2'
are both thin snapshots while 'thin_vol1' is thin origin (having
multiple snapshots).

Such reporting scheme provides much better base for selection criteria
in addition to providing more detailed information, for example:

$ lvs -a -o name,vg_name,lv_attr,layout,type -S 'type=metadata'
LV                   VG   Attr       Layout      Type
[lvol1_pmspare]      vg   ewi------- linear      metadata,pool,spare
[pool_tdata_rmeta_0] vg   ewi-aor--- linear      metadata,raid
[pool_tdata_rmeta_1] vg   ewi-aor--- linear      metadata,raid
[pool_tdata_rmeta_2] vg   ewi-aor--- linear      metadata,raid
[pool_tdata_rmeta_3] vg   ewi-aor--- linear      metadata,raid
[pool_tmeta]         vg   ewi-aor--- level1,raid metadata,pool,thin
[pool_tmeta_rmeta_0] vg   ewi-aor--- linear      metadata,raid
[pool_tmeta_rmeta_1] vg   ewi-aor--- linear      metadata,raid

(selected all LVs which are related to metadata of any type)

lvs -a -o name,vg_name,lv_attr,layout,type -S 'type={metadata,thin}'
LV           VG   Attr       Layout      Type
[pool_tmeta] vg   ewi-aor--- level1,raid metadata,pool,thin

(selected all LVs which hold metadata related to thin)

lvs -a -o name,vg_name,lv_attr,layout,type -S 'type={thin,snapshot}'
LV         VG   Attr       Layout     Type
thin_snap1 vg   Vwi---tz-k thin       snapshot,thin
thin_snap2 vg   Vwi---tz-k thin       snapshot,thin

(selected all LVs which are thin snapshots)

lvs -a -o name,vg_name,lv_attr,layout,type -S 'layout=raid'
LV           VG   Attr       Layout       Type
[pool_tdata] vg   rwi-aor--- level10,raid data,pool,thin
[pool_tmeta] vg   ewi-aor--- level1,raid  metadata,pool,thin

(selected all LVs with raid layout, any raid layout)

lvs -a -o name,vg_name,lv_attr,layout,type -S 'layout={raid,level1}'
  LV           VG   Attr       Layout      Type
  [pool_tmeta] vg   ewi-aor--- level1,raid metadata,pool,thin

(selected all LVs with raid level1 layout exactly)

And so on...