added experience tracking and automatic role assigning at given levels

includes: set role command to set a role to a given level (it clears out previous levels)
automatic level config generation on startup
min/max/multiplier configuration
job to persist the xp of the previous minute
added delayed scheduler start, so that events have a discord context in order to function
added role listener to automatically add and mark roles when they are created/deleted
fixed user in a server not being created correctly
added role service to give users role given by id
added server reference to role

abstracto-application/scheduling/scheduling-impl/src/main/java/dev/sheldan/abstracto/scheduling/config/SchedulerConfig.java

@@ -34,6 +34,7 @@ public class SchedulerConfig {
         SchedulerFactoryBean factory = new SchedulerFactoryBean();
         factory.setOverwriteExistingJobs(true);
         factory.setDataSource(dataSource);
+        factory.setAutoStartup(false);
         factory.setQuartzProperties(properties);
         factory.setJobFactory(jobFactory);
         return factory;

abstracto-application/scheduling/scheduling-impl/src/main/java/dev/sheldan/abstracto/scheduling/service/SchedulerServiceBean.java

@@ -158,4 +158,13 @@ public class SchedulerServiceBean implements SchedulerService {
             return false;
         }
     }
+
+    @Override
+    public void startScheduler() {
+        try {
+            schedulerFactoryBean.getScheduler().start();
+        } catch (SchedulerException e) {
+            log.error("Failed to start scheduler.", e);
+        }
+    }
 }