Chain Performance Testing

[elliotthenne]

Summary:

Added new functionality, can run either the iterative version (starting from 2 NFs to a specified # of max NFs) or the selective version. Added type checking at the beginning of the script so that it ensures the proper inputs are given. Recreated graph so that it looks cleaner. Made a copy of the data that can be viewed at the end of running.

Usage:

This PR includes
Resolves issues	Yes -- merge conflict
Breaking API changes
Internal API changes
Usability improvements
Bug fixes	Yes
New functionality
New NF/onvm_mgr args
Changes to starting NFs
Dependency updates
Web stats updates

Merging notes:

• Dependencies: None

TODO before merging :

• [ Yes] PR is ready for review

Test Plan:

Setup a server, make sure manager is working, make sure matplotlib library is installed, run ./test_performance [args] script

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