Major version including Landau-Lifschitz-Bloch

What's Changed

• make conv_with_function static by @dschick in #116
• Update LLB.convert_caresian_to_polar() by @Nilodirf in #130
• fix issue98: recursive atom mixed by @dschick in #133
• Implement backside excitation by @dschick in #132
• Implement LLB simulations by @dschick in #126

New Contributors

• @Nilodirf made their first contribution in #130

Full Changelog: v1.5.6...v2.0.0