Overhaul Test Suite

[jgray-19]

This pull request mainly changes the test suite for:

• NG vs PTC
• NG vs NG
• Convergence
• Plotting

Overall, the following has been changed

• Simplify test systems
• Separate files
• Add misalignment tests (Include translation)
• Add a ptc translation for misalignment map (will be in MAD-X pull request)

[ldeniau]

improve PTC mapdump names to sync with the entry and exit of NG