Making NekUpload Version Aware

NekUpload currently functions for datasets generated with version 5 of the software. Nektar++ will one day likely move into version 6, potentially introducing breaking changes to the file formats. NekUpload should be made version-aware, most likely through the workload manager in manager.py. It should first check the software version then call the correct sequence of tasks for the relevant software. The current code functions for V5 and it will allow easier addition of new checks for V6 in the future.