Move properties, parameters, events, and concepts around manual sections

The pages moved as follows:
  zpool-features.{5 => 7}
  spl{-module-parameters.5 => .4}
  zfs{-module-parameters.5 => .4}
  zfs-events.5 => into zpool-events.8
  zfsconcepts.{8 => 7}
  zfsprops.{8 => 7}
  zpoolconcepts.{8 => 7}
  zpoolprops.{8 => 7}

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Co-authored-by: Daniel Ebdrup Jensen <debdrup@FreeBSD.org>
Closes #12149
Closes #12212

man/man1/zhack.1

@@ -138,5 +138,5 @@ descriptions_obj:
 .
 .Sh SEE ALSO
 .Xr ztest 1 ,
-.Xr zpool-features 5 ,
+.Xr zpool-features 7 ,
 .Xr zfs 8

man/man1/ztest.1

@@ -230,4 +230,4 @@ By default the stack size is limited to
 .Xr zdb 1 ,
 .Xr zfs 1 ,
 .Xr zpool 1 ,
-.Xr spl-module-parameters 5
+.Xr spl 4