Skip coords with scalar values

[wd60622]

The plot_curve which power the media and fourier plotting functionality will fail while having scalar values in the coordinates.

This can be solved by using reset_coords method on the Dataset. However, this can be done internally

Setup:

from pymc_marketing.prior import Prior
from pymc_marketing.mmm import YearlyFourier

fourier = YearlyFourier(
    n_order=3,
    prior=Prior(
        "Laplace", 
        mu=0,
        b=Prior(
            "Gamma", 
            mu=1, 
            sigma=1, 
            dims=("geo", "fourier"),
        ), 
        dims=("geo", "fourier"), 
    ),
)

Before:

coords = {
    "geo": ["A", "B"], 
}
prior = fourier.sample_prior(coords=coords)
curve = fourier.sample_curve(prior)
fourier.plot_curve(curve.sel(geo="A").reset_coords("geo", drop=True))

After:

prior = fourier.sample_prior(coords=coords)
curve = fourier.sample_curve(prior)
fourier.plot_curve(curve.sel(geo="A"))