[v4.4] Relax term limit check in replica set to check for long long boundaries instead of int

In repl_set_config.cpp, we currently validate that the term lies within the valid range of an int. However, the term is stored as a long long throughout the code base. We should relax that check to be consistent.

This ticket only needs to be done in 4.4 and 4.2, since we moved the validation logic into an IDL file starting in 5.0, which does a check for int64, identical to long long