Add wb and wp to VMECIO.save

[ddudt]

Adds two additional quantities to the VMEC "wout" output. They are normalized versions of our "W_B" and "W_p" compute quantities.

[ddudt]

the $4\pi^2$ factor is related to the normalization for vp

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.62%. Comparing base (c1cf058) to head (22174d0).
Report is 5 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1475   +/-   ##
=======================================
  Coverage   95.62%   95.62%           
=======================================
  Files          98       98           
  Lines       25420    25420           
=======================================
+ Hits        24307    24309    +2     
+ Misses       1113     1111    -2     

Files with missing lines	Coverage Δ
desc/vmec.py	91.88% <100.00%> (ø)

... and 1 file with indirect coverage changes

[github-actions]

|             benchmark_name             |         dt(%)          |         dt(s)          |        t_new(s)        |        t_old(s)        | 
| -------------------------------------- | ---------------------- | ---------------------- | ---------------------- | ---------------------- |
 test_build_transform_fft_lowres         |     +3.30 +/- 13.46    | +1.73e-02 +/- 7.08e-02 |  5.43e-01 +/- 7.0e-02  |  5.26e-01 +/- 1.2e-02  |
 test_equilibrium_init_medres            |     +3.43 +/- 9.81     | +1.42e-01 +/- 4.05e-01 |  4.27e+00 +/- 4.0e-01  |  4.12e+00 +/- 3.1e-02  |
 test_equilibrium_init_highres           |     +0.93 +/- 0.96     | +5.00e-02 +/- 5.16e-02 |  5.42e+00 +/- 3.9e-02  |  5.37e+00 +/- 3.4e-02  |
 test_objective_compile_dshape_current   |     -0.01 +/- 0.70     | -3.64e-04 +/- 2.75e-02 |  3.93e+00 +/- 2.2e-02  |  3.93e+00 +/- 1.7e-02  |
 test_objective_compute_dshape_current   |     -0.10 +/- 3.21     | -5.26e-06 +/- 1.65e-04 |  5.15e-03 +/- 9.4e-05  |  5.16e-03 +/- 1.4e-04  |
 test_objective_jac_dshape_current       |     -1.55 +/- 9.00     | -6.72e-04 +/- 3.90e-03 |  4.26e-02 +/- 2.5e-03  |  4.33e-02 +/- 3.0e-03  |
 test_perturb_2                          |     -1.25 +/- 2.05     | -2.48e-01 +/- 4.07e-01 |  1.96e+01 +/- 3.5e-01  |  1.99e+01 +/- 2.0e-01  |
 test_proximal_freeb_jac                 |     -1.90 +/- 0.79     | -1.42e-01 +/- 5.90e-02 |  7.31e+00 +/- 3.3e-02  |  7.45e+00 +/- 4.9e-02  |
 test_solve_fixed_iter                   |     +0.26 +/- 2.37     | +8.75e-02 +/- 7.86e-01 |  3.32e+01 +/- 5.3e-01  |  3.31e+01 +/- 5.8e-01  |
 test_LinearConstraintProjection_build   |     -0.38 +/- 2.74     | -3.84e-02 +/- 2.81e-01 |  1.02e+01 +/- 2.2e-01  |  1.02e+01 +/- 1.8e-01  |
 test_build_transform_fft_midres         |     +8.41 +/- 6.51     | +5.06e-02 +/- 3.92e-02 |  6.52e-01 +/- 3.2e-02  |  6.01e-01 +/- 2.2e-02  |
 test_build_transform_fft_highres        |     +3.54 +/- 4.34     | +3.47e-02 +/- 4.26e-02 |  1.01e+00 +/- 2.6e-02  |  9.80e-01 +/- 3.4e-02  |
 test_equilibrium_init_lowres            |     +2.56 +/- 3.00     | +9.68e-02 +/- 1.13e-01 |  3.88e+00 +/- 3.7e-02  |  3.79e+00 +/- 1.1e-01  |
 test_objective_compile_atf              |     -0.15 +/- 4.60     | -1.18e-02 +/- 3.71e-01 |  8.07e+00 +/- 2.0e-01  |  8.08e+00 +/- 3.1e-01  |
 test_objective_compute_atf              |     -0.22 +/- 2.09     | -3.41e-05 +/- 3.31e-04 |  1.58e-02 +/- 2.2e-04  |  1.58e-02 +/- 2.5e-04  |
 test_objective_jac_atf                  |     -1.04 +/- 2.45     | -2.05e-02 +/- 4.82e-02 |  1.94e+00 +/- 4.1e-02  |  1.96e+00 +/- 2.5e-02  |
 test_perturb_1                          |     +0.81 +/- 5.19     | +1.18e-01 +/- 7.59e-01 |  1.48e+01 +/- 5.1e-01  |  1.46e+01 +/- 5.6e-01  |
 test_proximal_jac_atf                   |     +0.39 +/- 0.93     | +3.22e-02 +/- 7.61e-02 |  8.24e+00 +/- 6.1e-02  |  8.20e+00 +/- 4.5e-02  |
 test_proximal_freeb_compute             |     -0.58 +/- 1.07     | -1.15e-03 +/- 2.13e-03 |  1.98e-01 +/- 1.6e-03  |  1.99e-01 +/- 1.5e-03  |
 test_solve_fixed_iter_compiled          |     -2.48 +/- 2.94     | -5.51e-01 +/- 6.55e-01 |  2.17e+01 +/- 3.6e-01  |  2.23e+01 +/- 5.4e-01  |

[f0uriest]

Fix units