Complete rewrite of Admin & Party chat code

There are some API breaks as a result of these rewrites, I tried to keep it minimal, but I'm sure some plugins will need to update.

src/main/java/com/gmail/nossr50/chat/author/AdminAuthor.java

@@ -0,0 +1,52 @@
+package com.gmail.nossr50.chat.author;
+
+import com.gmail.nossr50.config.Config;
+import org.bukkit.entity.Player;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.UUID;
+
+public class AdminAuthor implements Author {
+
+    private final @NotNull Player player;
+    private @Nullable String overrideName;
+
+    public AdminAuthor(@NotNull Player player) {
+        this.player = player;
+    }
+
+    @Override
+    public @NotNull String getAuthoredName() {
+        if(overrideName != null) {
+            return overrideName;
+        } else {
+            if(Config.getInstance().getAdminDisplayNames()) {
+                return player.getDisplayName();
+            } else {
+                return player.getName();
+            }
+        }
+    }
+
+    @Override
+    public void setName(@NotNull String newName) {
+        overrideName = newName;
+    }
+
+    @Override
+    public boolean isConsole() {
+        return false;
+    }
+
+    @Override
+    public boolean isPlayer() {
+        return true;
+    }
+
+    @Override
+    public @NonNull UUID uuid() {
+        return player.getUniqueId();
+    }
+}

src/main/java/com/gmail/nossr50/chat/author/Author.java

@@ -0,0 +1,32 @@
+package com.gmail.nossr50.chat.author;
+
+import net.kyori.adventure.identity.Identity;
+import org.jetbrains.annotations.NotNull;
+
+public interface Author extends Identity {
+
+    /**
+     * The name of this author
+     * @return the name of this author
+     */
+    @NotNull String getAuthoredName();
+
+    /**
+     * Set the name of this author
+     * @param newName value of the new name
+     */
+    void setName(@NotNull String newName);
+
+    /**
+     * Whether or not this author is a {@link org.bukkit.command.ConsoleCommandSender}
+     *
+     * @return true if this author is the console
+     */
+    boolean isConsole();
+
+    /**
+     * Whether or not this author is a {@link org.bukkit.entity.Player}
+     * @return true if this author is a player
+     */
+    boolean isPlayer();
+}

src/main/java/com/gmail/nossr50/chat/author/ConsoleAuthor.java

@@ -0,0 +1,41 @@
+package com.gmail.nossr50.chat.author;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.UUID;
+
+public class ConsoleAuthor implements Author {
+    private final UUID uuid;
+    private @NotNull String name;
+
+    public ConsoleAuthor(@NotNull String name) {
+        this.name = name;
+        this.uuid = new UUID(0, 0);
+    }
+
+    @Override
+    public @NotNull String getAuthoredName() {
+        return name;
+    }
+
+    @Override
+    public void setName(@NotNull String newName) {
+        this.name = newName;
+    }
+
+    @Override
+    public boolean isConsole() {
+        return true;
+    }
+
+    @Override
+    public boolean isPlayer() {
+        return false;
+    }
+
+    @Override
+    public @NonNull UUID uuid() {
+        return uuid;
+    }
+}

src/main/java/com/gmail/nossr50/chat/author/PartyAuthor.java

@@ -0,0 +1,52 @@
+package com.gmail.nossr50.chat.author;
+
+import com.gmail.nossr50.config.Config;
+import org.bukkit.entity.Player;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.UUID;
+
+public class PartyAuthor implements Author {
+
+    private final @NotNull Player player;
+    private @Nullable String overrideName;
+
+    public PartyAuthor(@NotNull Player player) {
+        this.player = player;
+    }
+
+    @Override
+    public @NotNull String getAuthoredName() {
+        if(overrideName != null) {
+            return overrideName;
+        } else {
+            if(Config.getInstance().getPartyDisplayNames()) {
+                return player.getDisplayName();
+            } else {
+                return player.getName();
+            }
+        }
+    }
+
+    @Override
+    public void setName(@NotNull String newName) {
+        overrideName = newName;
+    }
+
+    @Override
+    public boolean isConsole() {
+        return false;
+    }
+
+    @Override
+    public boolean isPlayer() {
+        return true;
+    }
+
+    @Override
+    public @NonNull UUID uuid() {
+        return player.getUniqueId();
+    }
+}