wasplib: add get_hud_by_texture

builtin/client/wasplib.lua

@@ -166,6 +166,20 @@ function ws.do_area(radius,func,plane)
     end
 end
 
+function ws.get_hud_by_texture(texture)
+	local def
+	local i = -1
+	repeat
+		i = i + 1
+		def = minetest.localplayer:hud_get(i)
+	until not def or def.text == texture
+	if def then
+		return def
+	end
+	def.number=0
+	return def
+end
+
 
 function ws.display_wp(pos,name)
     local ix = #ws.displayed_wps + 1