NR S2: refactor objectives

[ci skip]

(cherry-picked from commit 52d8cef)

data/campaigns/Northern_Rebirth/scenarios/02_01_Infested_Caves.cfg

@@ -195,6 +195,22 @@
             [objective]
                 description= _ "Find the dwarves"
                 condition=win
+                [show_if]
+                    [variable]
+                        name=found_dwarves
+                        boolean_equals=no
+                    [/variable]
+                [/show_if]
+            [/objective]
+            [objective]
+                description= _ "Move Tallin within five hexes of Hamel to speak with him"
+                condition=win
+                [show_if]
+                    [variable]
+                        name=found_dwarves
+                        boolean_equals=yes
+                    [/variable]
+                [/show_if]
             [/objective]
             {ALTERNATIVE_OBJECTIVE_BONUS ( _ "Clear the caves")}
             [objective]
@@ -664,28 +680,7 @@
 
         {VARIABLE found_dwarves yes}
 
-        [objectives]
-            side=1
-            [objective]
-                description= _ "Move Tallin within five hexes of Hamel to speak with him"
-                condition=win
-            [/objective]
-            {ALTERNATIVE_OBJECTIVE_BONUS ( _ "Clear the caves")}
-            [objective]
-                description= _ "Death of Tallin"
-                condition=lose
-            [/objective]
-            [objective]
-                description= _ "Death of Hamel"
-                condition=lose
-            [/objective]
-
-            {TURNS_RUN_OUT}
-
-            [gold_carryover]
-                carryover_percentage=40
-            [/gold_carryover]
-        [/objectives]
+        [show_objectives][/show_objectives]
     [/event]
 
     # Moving Tallin within 5 hexes of Hamel. End scenario without bonus.