fix: Fixes ignoring mobs, champions, party crash, slayer rarity, boat speedhack, etc (#1222)

* Movie ignore mobiles to Mobile class
* Allow necromancer familiars to ignore mobiles
* ChampionSpawn should not quietly fail when creating new spawn
* Fix client party crash bug: 2 people partied, the leader logs out, other client is hung
* Fix spellbooks creating with magery/meditation only and creating magery multiple times
* Fix BaseRunicTool.GetRandomSlayer() creating more undead slayers than intended
* Do not allow players to dismount each other whilst mounted
* Fix AOS onwards damage increase tooltip and wrong formula in AOS
* Fix monsters killing other monster revenants + animate dead should not attack player pets + other animates
* Fix fire steed having loot pack added twice
* Fix oaks spawn not able to create Unicorns + Kirins via Activator.CreateInstace() due to constructor having name as parametr
* Fix ignoreMobiles flag not propagated to client for non-players.
* Fix harrower tents not leeching from players
* Fix boats speedhacking around the map
* Fix bless, agility etc. not renewing duration
* Fix reveal always worked
* Fix empty constructor for steeds so they don't throw now.

Projects/UOContent/Items/Weapons/SlayerGroup.cs

@@ -402,11 +402,13 @@ namespace Server.Items
             Groups = new[]
             {
                 humanoid,
-                undead,
                 elemental,
                 abyss,
                 arachnid,
                 reptilian,
+                // Skip undead for minor slayers
+                undead,
+                // Skip fey for random slayer
                 fey
             };