Fix vent critters spawn (#17833)

* VentCrittersRule scaling chance + spawn on station

* merge mouse migration and vent critters

* fix prototypes

* check if there is no valid locations

Resources/Prototypes/GameRules/events.yml

@@ -147,7 +147,19 @@
     minimumPlayers: 35
     weight: 5
     duration: 50
-  - type: MouseMigrationRule
+  - type: VentCrittersRule
+    entries:
+    - id: MobMouse
+      prob: 0.015
+    - id: MobMouse1
+      prob: 0.015
+    - id: MobMouse2
+      prob: 0.015
+    - id: MobRatServant
+      prob: 0.015
+    specialEntries:
+    - id: SpawnPointGhostRatKing
+      prob: 0.005
 
 - type: entity
   id: PowerGridCheck
@@ -230,14 +242,11 @@
   - type: VentCrittersRule
     entries:
     - id: MobMouse
-      amount: 4
-      maxAmount: 12
+      prob: 0.02
     - id: MobMouse1
-      amount: 4
-      maxAmount: 12
+      prob: 0.02
     - id: MobMouse2
-      amount: 4
-      maxAmount: 12
+      prob: 0.02
 
 - type: entity
   id: SlimesSpawn
@@ -251,15 +260,12 @@
     duration: 60
   - type: VentCrittersRule
     entries:
-      - id: MobAdultSlimesBlueAngry
-        amount: 6
-        maxAmount: 10
-      - id: MobAdultSlimesGreenAngry
-        amount: 6
-        maxAmount: 10
-      - id: MobAdultSlimesYellowAngry
-        amount: 6
-        maxAmount: 10
+    - id: MobAdultSlimesBlueAngry
+      prob: 0.02
+    - id: MobAdultSlimesGreenAngry
+      prob: 0.02
+    - id: MobAdultSlimesYellowAngry
+      prob: 0.02
 
 - type: entity
   id: SpiderSpawn
@@ -273,9 +279,8 @@
     duration: 60
   - type: VentCrittersRule
     entries:
-      - id: MobGiantSpiderAngry
-        amount: 4
-        maxAmount: 8
+    - id: MobGiantSpiderAngry
+      prob: 0.05
 
 - type: entity
   id: SpiderClownSpawn
@@ -289,9 +294,8 @@
     duration: 60
   - type: VentCrittersRule
     entries:
-      - id: MobClownSpider
-        amount: 4
-        maxAmount: 8
+    - id: MobClownSpider
+      prob: 0.05
 
 - type: entity
   id: ZombieOutbreak