Implement SMSG_SPELLENERGIZELOG and fix missing combat text cases

Parse SPELLENERGIZELOG (victim/caster packed GUIDs + spellId + powerType +
amount) and emit ENERGIZE combat text for mana/energy gains.  Add ENERGIZE
to CombatTextEntry::Type enum (blue +N text).

Also add explicit renderCombatText cases for BLOCK, PERIODIC_DAMAGE,
PERIODIC_HEAL, and ENVIRONMENTAL — previously all fell through to the
colourless default handler.

include/game/spell_defines.hpp

@@ -50,7 +50,8 @@ struct ActionBarSlot {
 struct CombatTextEntry {
     enum Type : uint8_t {
         MELEE_DAMAGE, SPELL_DAMAGE, HEAL, MISS, DODGE, PARRY, BLOCK,
-        CRIT_DAMAGE, CRIT_HEAL, PERIODIC_DAMAGE, PERIODIC_HEAL, ENVIRONMENTAL
+        CRIT_DAMAGE, CRIT_HEAL, PERIODIC_DAMAGE, PERIODIC_HEAL, ENVIRONMENTAL,
+        ENERGIZE
     };
     Type type;
     int32_t amount = 0;