filesort() uses file->estimate_rows_upper_bound() call to allocate
internal buffers. If this function returns a value smaller than
a number of row that will be returned later in find_all_keys(),
that can cause server crash.
Fixed by implementing ha_federated::estimate_rows_upper_bound() to
return maximum possible number of rows.
Present estimation for FEDERATED always returns 0 if the linked to the VIEW.


mysql-test/r/federated.result:
  Bug #32374 crash with filesort when selecting from federated table and view.
  
  test result
mysql-test/t/federated.test:
  Bug #32374 crash with filesort when selecting from federated table and view.
  
  test case
sql/ha_federated.cc:
  Bug #32374 crash with filesort when selecting from federated table and view.
  
  ha_federated::estimate_rows_upper_bound() implemented
sql/ha_federated.h:
  Bug #32374 crash with filesort when selecting from federated table and view.
  
  ha_federated::estimate_rows_upper_bound() interface