equip_slot_by_name(): Remove duplicated list and catch "Body Armour"

Allows Lua API's `item.equip_type` to work with `l_item_equipped_at()` and `l_slot_is_available()`.
Previously didn't work for body armour.

`s_equip_slot_names` was only created to support this function afaict, and just shadows `enum equipment_slot`.
It's not used anywhere else and afaict was just tech debt.

Tested locally and everything works as before, just with the body armour improvement.

Author: brianfaires

crawl-ref/settings/crawl-rc

@@ -0,0 +1 @@
+Subproject commit 2dd35f34996ff21cdb522f328c9a9f4bfadd0ec2

crawl-ref/source/output.cc

@@ -1999,17 +1999,15 @@ int update_monster_pane()
 }
 #endif
 
-static const char *s_equip_slot_names[] =
-{
-    "Weapon", "Offhand", "Armour", "Helmet", "Gloves", "Boots",
-    "Barding", "Cloak", "Ring", "Amulet", "Gizmo"
-};
-
 int equip_slot_by_name(const char *s)
 {
     for (int i = SLOT_FIRST_STANDARD; i <= SLOT_LAST_STANDARD; ++i)
-        if (!strcasecmp(s_equip_slot_names[i - SLOT_FIRST_STANDARD], s))
+    {
+        equipment_slot slot = static_cast<equipment_slot>(i);
+        if (!strcasecmp(s, equip_slot_name(slot, true)) || 
+            !strcasecmp(s, equip_slot_name(slot, false)))
             return i;
+    }
 
     return -1;
 }