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-int/src/main/java/dev/sheldan/abstracto/scheduling/service/SchedulerService.java

@@ -23,4 +23,6 @@ public interface SchedulerService {
     boolean executeJob(SchedulerJob job);
 
     boolean executeJobWithParametersOnce(String name, String group, JobDataMap dataMap, Date date);
+
+    void startScheduler();
 }