Remove vaccum objective option from Equilibrium.solve

[f0uriest]

• Removes "vacuum" option from Equilibrium.solve, solve_continuation and get_equilibrium_objective, since it is non-trivial to check that the user didn't make a mistake with assigning compatible profiles.
• Keeps the option from the input file, but now just switches to force balance and explicitly drops any user supplied profiles and warns.

Resolves #809

[github-actions]

|             benchmark_name             |         dt(%)          |         dt(s)          |        t_new(s)        |        t_old(s)        | 
| -------------------------------------- | ---------------------- | ---------------------- | ---------------------- | ---------------------- |
 test_build_transform_fft_lowres         |     -0.23 +/- 1.61     | -4.17e-03 +/- 2.88e-02 |  1.78e+00 +/- 2.6e-02  |  1.79e+00 +/- 1.2e-02  |
 test_build_transform_fft_midres         |     -0.15 +/- 1.73     | -2.86e-03 +/- 3.40e-02 |  1.96e+00 +/- 3.3e-02  |  1.96e+00 +/- 7.8e-03  |
 test_build_transform_fft_highres        |     -0.63 +/- 1.28     | -1.48e-02 +/- 3.03e-02 |  2.34e+00 +/- 1.6e-02  |  2.36e+00 +/- 2.6e-02  |
 test_equilibrium_init_lowres            |     +0.27 +/- 0.47     | +2.57e-02 +/- 4.49e-02 |  9.62e+00 +/- 3.1e-02  |  9.59e+00 +/- 3.3e-02  |
 test_equilibrium_init_medres            |     -0.41 +/- 2.54     | -4.23e-02 +/- 2.61e-01 |  1.02e+01 +/- 1.1e-01  |  1.03e+01 +/- 2.4e-01  |
 test_equilibrium_init_highres           |     -0.22 +/- 0.86     | -2.64e-02 +/- 1.04e-01 |  1.21e+01 +/- 7.2e-02  |  1.21e+01 +/- 7.5e-02  |
 test_objective_compile_dshape_current   |     -0.59 +/- 9.86     | -2.31e-02 +/- 3.84e-01 |  3.87e+00 +/- 2.7e-01  |  3.90e+00 +/- 2.7e-01  |
 test_objective_compile_atf              |     +0.69 +/- 5.83     | +5.09e-02 +/- 4.32e-01 |  7.46e+00 +/- 2.7e-01  |  7.41e+00 +/- 3.3e-01  |
 test_objective_compute_dshape_current   |     -1.41 +/- 1.57     | -7.53e-05 +/- 8.34e-05 |  5.25e-03 +/- 5.8e-05  |  5.32e-03 +/- 6.0e-05  |
 test_objective_compute_atf              |     +1.54 +/- 1.41     | +3.01e-04 +/- 2.74e-04 |  1.98e-02 +/- 2.2e-04  |  1.95e-02 +/- 1.6e-04  |
 test_objective_jac_dshape_current       |     +7.55 +/- 5.18     | +2.95e-03 +/- 2.02e-03 |  4.21e-02 +/- 1.5e-03  |  3.91e-02 +/- 1.4e-03  |
 test_objective_jac_atf                  |     +0.58 +/- 3.07     | +1.08e-02 +/- 5.73e-02 |  1.87e+00 +/- 2.5e-02  |  1.86e+00 +/- 5.2e-02  |
 test_perturb_1                          |     -0.80 +/- 3.55     | -1.24e-01 +/- 5.48e-01 |  1.53e+01 +/- 3.8e-01  |  1.54e+01 +/- 4.0e-01  |
 test_perturb_2                          |     -1.39 +/- 1.31     | -2.82e-01 +/- 2.66e-01 |  2.01e+01 +/- 2.5e-01  |  2.04e+01 +/- 9.6e-02  |
 test_proximal_jac_atf                   |     +0.17 +/- 1.33     | +1.19e-02 +/- 9.47e-02 |  7.13e+00 +/- 6.4e-02  |  7.11e+00 +/- 7.0e-02  |
 test_proximal_freeb_compute             |     -1.24 +/- 0.86     | -1.54e-03 +/- 1.07e-03 |  1.22e-01 +/- 8.8e-04  |  1.24e-01 +/- 6.1e-04  |
 test_proximal_freeb_jac                 |     +0.08 +/- 1.06     | +5.50e-03 +/- 7.40e-02 |  6.98e+00 +/- 3.7e-02  |  6.98e+00 +/- 6.4e-02  |

[f0uriest]

previously this was writing the wrong mode numbers if the profiles were even power series. The logic above now copies them all to a non-symmetric basis before outputting

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.71%. Comparing base (68c971f) to head (1e0def0).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #933      +/-   ##
==========================================
- Coverage   94.71%   94.71%   -0.01%     
==========================================
  Files          86       86              
  Lines       21198    21207       +9     
==========================================
+ Hits        20078    20086       +8     
- Misses       1120     1121       +1     

Files	Coverage Δ
desc/continuation.py	93.60% <ø> (ø)
desc/equilibrium/equilibrium.py	96.63% <ø> (ø)
desc/input_reader.py	91.90% <100.00%> (+0.10%)	⬆️
desc/objectives/getters.py	85.93% <100.00%> (-1.95%)	⬇️

[dpanici]

Changed my only gripe (the warning), I approve now