Adapt LoChat for Minecraft 1.20.1 Paper

- Changed dependency from Folia API 1.21.4 to Paper API 1.20.1
- Updated plugin.yml: api-version to 1.20, folia-supported to false
- Replaced Folia-specific scheduler calls with FoliaUtil for compatibility
- Updated version to 1.5.5-1.20.1
- Fixed enum switch warning in ChatListener
- Removed unused imports
- All tests pass successfully

bin/main/plugin.yml

@@ -1,10 +1,10 @@
 name: LoChat
-version: '1.5.5'
+version: '1.5.5-1.20.1'
 main: com.loki.lochat.LoChat
-api-version: '1.21'
-folia-supported: true
+api-version: '1.20'
+folia-supported: false
 author: loki
-description: Advanced chat plugin for Folia with gradient nicks
+description: Advanced chat plugin for Paper 1.20.1 with gradient nicks
 
 softdepend:
   - PlaceholderAPI