int cannot be used anymore to change a group, only ExclusiveGroups from now on

fix code for entity operation submission
clarify variable names

improve throwing of exceptions

improved tracking of entity groups (maybe fixed some bugs)

improve code
add more debug  checks

renamed UnityEntiySubmissionScheduler

Split ExecuteOnEntities functions to another class
Added the index element in ExecuteOnEntities so that is possible to know the current index of the iteration

tinkering around the concept of QueryMappedEntities