Fix showtooltip icon fallback to use tooltip texture before question mark

When #showtooltip is used without an explicit spell/item argument and all
conditionals fail, the icon now falls back to the tooltip texture (first
action) instead of immediately showing a question mark. This prevents the
question mark icon from appearing when the macro has valid actions but none
of their conditions are currently met.

Fixes issue where macro icon becomes question mark when no target and
Battle Shout buff is already active.

Core.lua

@@ -2422,6 +2422,12 @@ function GetActionTexture(slot)
         -- This block handles the case where all conditionals fail and no explicit
         -- #showtooltip was set. It defaults to the macro's chosen icon (e.g., the red '?')
         if not actions.active and not actions.explicitTooltip and actions.list and table.getn(actions.list) > 0 then
+            -- First try to use the tooltip texture if it exists
+            if actions.tooltip and actions.tooltip.texture then
+                return actions.tooltip.texture
+            end
+
+            -- Then try to get the macro's own icon
             local macroName = GetActionText(slot)
             if macroName then
                 local macroID = GetMacroIndexByName(macroName)