Eliminate the redundant UnsupportedScopeOrder exception classes
We have a definition for the UnsupportedScopeOrder
Exception class in three different files:
lib/gitlab/pagination/keyset/iterator.rb
lib/gitlab/pagination/keyset/paginator.rb
lib/gitlab/pagination/keyset/in_operator_optimization/query_builder.rb
Let's create a standalone error class where we store the default error message as well, for example:
unless success
raise UnsupportedScopeOrder
end