Add atmospheric drag effect for Brouwer-Lyddane model
This issue is related to the discussion during the fix of #869 (closed). Warren Phipps's 1992 thesis [1] presents an analytical model for the atmospheric drag that is suited for the Brouwer-Lyddane orbit propagator.
Reference [2] highlights the benefits of the drag augmented Brouwer-Lyddane orbit propagator for low Earth satellite orbit determination. Therefore, having this new feature could be interesing.
[1] https://apps.dtic.mil/sti/pdfs/ADA256133.pdf
[2] https://calhoun.nps.edu/bitstream/handle/10945/34052/danielson_comparison.pdf?sequence=1&isAllowed=y