Intraday heatmap should support automatically adding sunrise/sunset lines

[AdamRJensen]

Currently, the sunrise/sunset lines need to be added separately which is a hassle.

I am imagining that two additional parameters can be added (latitude/longitude), which defaults to None (optional) and when they are both specified, then sunset/sunrise lines are added.

fig, ax = plt.subplots(figsize=(6, 3))

_ = solarpy.plotting.plot_intraday_heatmap(
    time=data.index,
    values=data["ghi"],
    cmap=cmap,
    norm=norm,
    colorbar_label="GHI [W/m²]",
    ax=ax,  # pass in existing axes
)

# Overlay sunrise and sunset times
sun_rise_set = pvlib.solarposition.sun_rise_set_transit_spa(
    pd.date_range(data.index.min(), data.index.max(), freq="1d"),
    meta["latitude"],
    meta["longitude"],
)

sunrise = (
    sun_rise_set["sunrise"] - sun_rise_set["sunrise"].index.normalize()
).dt.total_seconds() / 3600

sunset = (
    sun_rise_set["sunset"] - sun_rise_set["sunset"].index.normalize()
).dt.total_seconds() / 3600


ax.plot(sunrise, c="r", linestyle="dashed", lw=1.5, alpha=0.7)
ax.plot(sunset, c="r", linestyle="dashed", lw=1.5, alpha=0.7)