CorpseNotoriety returned Murderer for a player corpse whenever the corpse body was a monster
body. RunUO's check was `body.IsMonster && IsSummoned(owner)`, which is never true for a player;
the second half was lost when the branch was simplified (#134). Players who died while
polymorphed or in a necromancer form left a corpse with the wrong notoriety.
Player corpses also check murderer and criminal status before guild standing again, matching
RunUO and MobileNotoriety.
Tests: UOContent.Tests 1162 passed (4 new CorpseNotorietyTests).