Fix getMemberOrNull and getGuildMembers caching only user data (#964)

As reported in the Kord Discord server [1], these methods of
StoreEntitySupplier are storing the results only to the UserData cache,
not the MemberData cache, so subsequent calls would not find them from
the cache.

When using cacheWithCachingRestFallback, this results in REST calls
being made every single time to get members, unless they got cached from
a gateway event.

[1] https://discord.com/channels/556525343595298817/1271484633610981493

core/src/commonMain/kotlin/supplier/StoreEntitySupplier.kt

@@ -60,9 +60,11 @@ public class StoreEntitySupplier(
 
     }
 
-    override suspend fun getMemberOrNull(guildId: Snowflake, userId: Snowflake): Member? {
-        return storeAndReturn(supplier.getMemberOrNull(guildId, userId)) { it.data }
-    }
+    override suspend fun getMemberOrNull(guildId: Snowflake, userId: Snowflake): Member? =
+        supplier.getMemberOrNull(guildId, userId)?.also { member ->
+            cache.put(member.data)
+            cache.put(member.memberData)
+        }
 
     override suspend fun getMessageOrNull(channelId: Snowflake, messageId: Snowflake): Message? {
         return storeAndReturn(supplier.getMessageOrNull(channelId, messageId)) { it.data }
@@ -104,9 +106,11 @@ public class StoreEntitySupplier(
         return storeOnEach(supplier.getGuildBans(guildId, limit)) { it.data }
     }
 
-    override fun getGuildMembers(guildId: Snowflake, limit: Int?): Flow<Member> {
-        return storeOnEach(supplier.getGuildMembers(guildId, limit)) { it.data }
-    }
+    override fun getGuildMembers(guildId: Snowflake, limit: Int?): Flow<Member> =
+        supplier.getGuildMembers(guildId, limit).onEach { member ->
+            cache.put(member.data)
+            cache.put(member.memberData)
+        }
 
     override fun getGuildVoiceRegions(guildId: Snowflake): Flow<Region> {
         return storeOnEach(supplier.getGuildVoiceRegions(guildId)) { it.data }