GH-197 Multification setup

[CitralFlo]

This pull request includes several changes to integrate the Multification library into the EternalCombat plugin, refactor notification handling, and remove unused code. The most important changes include adding Multification dependencies, updating the notification system, and removing the FightBossBarService class.

Multification Integration:

• buildSrc/src/main/kotlin/Versions.kt: Added MULTIFICATION constant.
• eternalcombat-plugin/build.gradle.kts: Added Multification dependencies and updated shadowJar configuration. [1] [2]

Notification System Refactor:

• eternalcombat-plugin/src/main/java/com/eternalcode/combat/EternalCombatReloadCommand.java: Replaced Formatter with Multification Notice for reload messages. [1] [2] [3]
• eternalcombat-plugin/src/main/java/com/eternalcode/combat/config/implementation/PluginConfig.java: Updated notification messages to use Multification Notice. [1] [2]

Code Cleanup:

• eternalcombat-plugin/src/main/java/com/eternalcode/combat/CombatPlugin.java: Removed FightBossBarService and updated related code. [1] [2] [3] [4]
• eternalcombat-plugin/src/main/java/com/eternalcode/combat/fight/FightTagCommand.java: Refactored to use Multification Notice for combat status and tag messages. [1] [2] [3]

[CitralFlo]

Will be tested in the future, waiting for bossbar merge in Multification