Small improvements (#22)

* Remove sky color hardcoding

* Bind to available port instead of 25565

* Fix error class and reduce accessors

* Fix language errors

* Cleanup imports and remove weird behaviour

* Print properly message

* Print version name

* Bump gson, update API usage and use linkedhashset over list

* Reimplement approach to categories

* Enable all feature flags by default

* Use jul instead of slf4j

* Call mc repo before maven central to fix build on mac

common/build.gradle

@@ -1,13 +1,11 @@
 plugins {
-    id 'java'
+    id 'java-library'
 }
 
 dependencies {
-    compileOnly 'com.google.code.gson:gson:2.10.1'
+    api 'com.google.code.gson:gson:2.10.1'
     implementation 'io.github.classgraph:classgraph:4.8.172'
     implementation "net.lenni0451:Reflect:1.3.3"
-    implementation 'org.slf4j:slf4j-api:2.0.13'
-    implementation "org.slf4j:jul-to-slf4j:2.0.13"
 }
 
 tasks.withType(JavaCompile).configureEach {
@@ -16,6 +14,6 @@ tasks.withType(JavaCompile).configureEach {
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(17))
+        languageVersion.set(JavaLanguageVersion.of(21))
     }
 }