Make slash commands interface and load them dynamically

Slash commands are now loaded dynamically by implementing a SlashCommand interface and storing them in a loaded commands map.

src/main/java/wtf/beatrice/hidekobot/commands/slash/CoinFlipCommand.java

@@ -9,16 +9,23 @@ import net.dv8tion.jda.api.interactions.components.ActionRow;
 import net.dv8tion.jda.api.interactions.components.buttons.Button;
 import org.jetbrains.annotations.NotNull;
 import wtf.beatrice.hidekobot.Cache;
+import wtf.beatrice.hidekobot.objects.SlashCommand;
 import wtf.beatrice.hidekobot.util.RandomUtil;
 
 import java.util.List;
 
-public class CoinFlipCommand
+public class CoinFlipCommand implements SlashCommand
 {
 
+    @Override
+    public String getCommandName() {
+        return "coinflip";
+    }
+
     private final Button reflipButton = Button.primary("coinflip_reflip", "Flip again")
             .withEmoji(Emoji.fromFormatted("\uD83E\uDE99"));
 
+    @Override
     public void runSlashCommand(@NotNull SlashCommandInteractionEvent event)
     {
         // perform coin flip