NR: Refactor the White Magi respawn location finding code into a macro

This bit was subject to a particularly bad case of code copy-pasting
when the only real variable is the id of the first respawn hub
candidate.

Added a statement to clear the respawn_hub WML variable after running
the code since it's never used again afterwards.

data/campaigns/Northern_Rebirth/utils/herodeaths.cfg

@@ -214,6 +214,52 @@
     {VARIABLE Eryssa_alive no}
 [/event]
 
+#define FIND_NR_WHITE_MAGE_RESPAWN HUB_CANDIDATE
+    # Find a respawn point, start within 1 hex of the candidate, increase range if nothing suitable
+    # Search around Tallin if the candidate is still jailed
+    {VARIABLE current_radius 1}
+    [if]
+        [have_unit]
+            id={HUB_CANDIDATE}
+        [/have_unit]
+        [then]
+            {VARIABLE respawn_hub ({HUB_CANDIDATE})}
+        [/then]
+        [else]
+            {VARIABLE respawn_hub (Tallin)}
+        [/else]
+    [/if]
+    [while]
+        [variable]
+            name=respawn_point.length
+            equals=0
+        [/variable]
+        [do]
+            [store_locations]
+                variable=respawn_point
+                [and]
+                    [filter]
+                        id=$respawn_hub
+                    [/filter]
+                    radius=$current_radius
+                [/and]
+                # Exclude hexes with units on them and impassable terrain
+                [and]
+                    [not]
+                        [filter]
+                        [/filter]
+                    [/not]
+                    [not]
+                        terrain=Wo,*^Xm,X*,Q*
+                    [/not]
+                [/and]
+            [/store_locations]
+            {VARIABLE_OP current_radius add 1}
+        [/do]
+    [/while]
+    {CLEAR_VARIABLE current_radius,respawn_hub}
+#enddef
+
 # Sister Thera death, seven randomly chosen dialogues
 [event]
     name=last breath
@@ -326,48 +372,9 @@
         [/else]
     [/switch]
     {FLASH_WHITE ()}
-    # Find a respawn point, start within 1 hex of Father Morvin, increase range if nothing suitable
-    # Search around Tallin if Morvin is still jailed
-    {VARIABLE current_radius 1}
-    [if]
-        [have_unit]
-            id=Father Morvin
-        [/have_unit]
-        [then]
-            {VARIABLE respawn_hub "Father Morvin"}
-        [/then]
-        [else]
-            {VARIABLE respawn_hub "Tallin"}
-        [/else]
-    [/if]
-    [while]
-        [variable]
-            name=respawn_point.length
-            equals=0
-        [/variable]
-        [do]
-            [store_locations]
-                variable=respawn_point
-                [and]
-                    [filter]
-                        id=$respawn_hub
-                    [/filter]
-                    radius=$current_radius
-                [/and]
-                # Exclude hexes with units on them and impassable terrain
-                [and]
-                    [not]
-                        [filter]
-                        [/filter]
-                    [/not]
-                    [not]
-                        terrain=Wo,*^Xm,X*,Q*
-                    [/not]
-                [/and]
-            [/store_locations]
-            {VARIABLE_OP current_radius add 1}
-        [/do]
-    [/while]
+
+    {FIND_NR_WHITE_MAGE_RESPAWN (Father Morvin)}
+
     # Store unit to check if it advanced to mage of light
     [store_unit]
         [filter]
@@ -392,9 +399,7 @@
         [/modifications]
         {IS_LOYAL}
     [/unit]
-    {CLEAR_VARIABLE respawn_point}
-    {CLEAR_VARIABLE type_check}
-    {CLEAR_VARIABLE current_radius}
+    {CLEAR_VARIABLE respawn_point,type_check}
     [switch]
         variable=random
         [case]
@@ -615,46 +620,8 @@
         [/else]
     [/switch]
 
-    {VARIABLE current_radius 1}
-    [if]
-        [have_unit]
-            id=Sister Thera
-        [/have_unit]
-        [then]
-            {VARIABLE respawn_hub "Sister Thera"}
-        [/then]
-        [else]
-            {VARIABLE respawn_hub "Tallin"}
-        [/else]
-    [/if]
-    [while]
-        [variable]
-            name=respawn_point.length
-            equals=0
-        [/variable]
-        [do]
-            [store_locations]
-                variable=respawn_point
-                [and]
-                    [filter]
-                        id=$respawn_hub
-                    [/filter]
-                    radius=$current_radius
-                [/and]
-                # Exclude hexes with units on them and impassable terrain
-                [and]
-                    [not]
-                        [filter]
-                        [/filter]
-                    [/not]
-                    [not]
-                        terrain=Wo,*^Xm,X*,Q*
-                    [/not]
-                [/and]
-            [/store_locations]
-            {VARIABLE_OP current_radius add 1}
-        [/do]
-    [/while]
+    {FIND_NR_WHITE_MAGE_RESPAWN (Sister Thera)}
+
     [store_unit]
         [filter]
             id=Father Morvin
@@ -678,9 +645,7 @@
         [/modifications]
         {IS_LOYAL}
     [/unit]
-    {CLEAR_VARIABLE type_check}
-    {CLEAR_VARIABLE respawn_point}
-    {CLEAR_VARIABLE current_radius}
+    {CLEAR_VARIABLE type_check,respawn_point}
 
     [switch]
         variable=random
@@ -786,6 +751,8 @@
     [/clear_variable]
 [/event]
 
+#undef FIND_NR_WHITE_MAGE_RESPAWN
+
 # Elenia death
 [event]
     name=last breath