Implemented enums

server/core/src/main/java/fr/univnantes/software_engineering/enums/Action.java

+package fr.univnantes.software_engineering.enums;
+
+public enum Action
+{
+    USE_CARD,
+    UPGRADE_WONDER,
+    DISCARD
+}

server/core/src/main/java/fr/univnantes/software_engineering/enums/Age.java

+package fr.univnantes.software_engineering.enums;
+
+public enum Age
+{
+    AGE1,
+    AGE2,
+    AGE3
+}

server/core/src/main/java/fr/univnantes/software_engineering/enums/GameState.java

+package fr.univnantes.software_engineering.enums;
+
+public enum GameState
+{
+    WAITING,
+    STARTED,
+    FULL
+}

server/core/src/main/java/fr/univnantes/software_engineering/enums/Resource.java

+package fr.univnantes.software_engineering.enums;
+
+public enum Resource
+{
+    CLAY,
+    STONE,
+    WOOD,
+    ORE,
+    CLOTH,
+    GLASS,
+    PAPYRUS
+}

server/core/src/main/java/fr/univnantes/software_engineering/enums/WonderEffect.java

+package fr.univnantes.software_engineering.enums;
+
+public enum WonderEffect
+{
+    ADD_SHIELDS,
+    ADD_RAW_MATERIAL,
+    ADD_GOLD,
+    ADD_SCIENCE_SYMBOL,
+    BUILD_FREE,
+    CHOOSE_CARD_FROM_DISCARD_THE_BUILD_FREE,
+    ADD_VICTORY_POINTS
+}