[core] Introduce junit5 (knowm#4725)

* [core] Add support for junit 5

* [core] Fix wrong parent version

* [core] Set code level to java 11

* Set project code style to java 8

pom.xml

@@ -36,7 +36,7 @@
     <version.fasterxml>2.14.1</version.fasterxml>
     <version.github.mmazi>3.0</version.github.mmazi>
     <version.resilience4j>1.7.0</version.resilience4j>
-    <version.junit>4.13.2</version.junit>
+    <version.junit>5.9.3</version.junit>
     <version.lombok>1.18.26</version.lombok>
     <version.knowm.xchart>3.8.2</version.knowm.xchart>
     <version.qos.logback>1.4.5</version.qos.logback>
@@ -387,11 +387,12 @@
 
     <!-- JUnit for testing -->
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
+      <groupId>org.junit.vintage</groupId>
+      <artifactId>junit-vintage-engine</artifactId>
       <version>${version.junit}</version>
       <scope>test</scope>
     </dependency>
+
     <dependency>
       <groupId>org.assertj</groupId>
       <artifactId>assertj-core</artifactId>