PR for G2RT into main branch

[zixuan-w]

Please see the test function below. Please let me know if you need help with anything! Thanks.

def test_g2rt():
    from numpy.testing import assert_allclose
    from exposan import g2rt

    rtol = 0.01
    
    modelA = g2rt.create_model('A')
    dfA = modelA.metrics_at_baseline()
    valuesA = [534.561, 1.34665, 396.737]
    assert_allclose(dfA.values, valuesA, rtol=rtol)
    
    modelB = g2rt.create_model('B')
    dfB = modelB.metrics_at_baseline()
    valuesB = [754.523, 1.66349, 470.437]
    assert_allclose(dfB.values, valuesB, rtol=rtol)

[yalinli2]

This looks good to me, as long as QSDsan's side is good, we can merge this in.

[yalinli2]

The failed test was due to the changes in SludgePasteurization, leading to different results in reclaimer.SysA, I've opened a new issue related to this. I'll fix the metric when that is done. Good to merge in the g2rt systems.