Interface for effects and budget optimization

[felipeangelimvieira]

Ideal optimization interface:

from prophetverse.mmm.optimization import BudgetOptimizer


optimizer = BudgetOptimizer(
      model,
      fh=pd.period_range("2024-01-01", "2024-12-31", freq="D"),
      budget=1e6,
      variables_to_optimize=["channel1", "channel2"],
      unit_cost=[1, 1],
)

Internally the optimizer should call scipy.minimize, with an objective function that receives the values for each channel and returns the output of the forecast for the period. It would be interesting to allow optimization of share per day-channel, or share per channel.