Modification to shock_decomposition and plot_decomposition interfaces to include flexibility with dates
Include the following options for dates when shock_decomposition is triggered:
date of the start of the decomposition, default: start of the estimation sample (some people may want to start the decomposition with the smoothed value at the end of the sample). Proposed option name:
init_date = INTEGER.
date of the start of the graph, default: start of the estimation sample. Proposed option name:
graph_init_date = INTEGER.