ID excitation data generation

[JeffersonBarrosVieira]

Creating the file to generate the excitation tables for the IDs and generating the excitation tables for the IDs to be used in control-system-constants repos: excitation-data

[xresende]

nice, @JeffersonBarrosVieira !

suggestions:

1. add "footer" texts as undulator class constants
2. in these classes also add methods to: a) generate header and footer texts, b) tables

I think this way these classes become self contained in terms of undulator parameters.