Fix totem casts erroring when a totem's cooldown was never read

GetTotemDurationAndHealth reads the totem description from tooltip line 5.
When that line was empty it returned only duration and health, so the
three-value assignment in ScanTotems left the rank's Cooldown nil, and
dropping that totem failed in ActivateTotem with
"COE_TotemLogic.lua:776: attempt to compare number with nil".

- Always return duration, health and cooldown.
- When line 5 is empty, read the description from the last tooltip line.
  It moves up when the tooltip is shorter, e.g. without the "Tools:" line
  while the totem item is not in the item cache.
- Clear line 5 before SetSpell so a shorter tooltip cannot reuse the
  previous totem's text.

COE_TotemData.lua

@@ -464,13 +464,26 @@ end
 -------------------------------------------------------------------]]
 function COE:GetTotemDurationAndHealth(spellid)
 
+    COETotemTTTextLeft5:SetText(nil);
     COETotemTTTextRight3:SetText(nil);
     COETotemTT:SetSpell(spellid, BOOKTYPE_SPELL);
     text = COETotemTTTextLeft5:GetText();
 
+    -- the description is normally line 5 but moves up when the client
+    -- leaves out the "Tools:" line (totem item not in the item cache).
+    -- the description is always the last line
+    -- -----------------------------------------------------------------
+    if (not text) then
+        local last = getglobal("COETotemTTTextLeft" .. COETotemTT:NumLines());
+        if (last) then text = last:GetText(); end
+    end
+
+    -- callers assign all three values: returning fewer leaves the
+    -- rank's Cooldown nil and the cast errors in ActivateTotem
+    -- ------------------------------------------------------------
     if (not text) then
         COE:DebugMessage("nil text with id: " .. spellid);
-        return 0, 0;
+        return 0, 0, 0;
     end
 
     local duration = 0;