main_plot_handler: Handles plotting parameter models
In tinnaing347/bRema: Building Energy Modelling and Analysis Tool in R

This function handles the general scheme of plotting parameters model by using plotly. Uses main_line_point_plot and plot_point functions to handle and draw graphs.

1 2	main_plot_handler(util, best_model, energy, b_name = "", unretrofit_flag = TRUE)

`util`	A data frame with columns: OAT, usage, estimated (1 for estimated usage and 0 for actual usage) and prepost (1 for unretrofit and pre-retrofit and 3 for post-retrofit). See `unretrofit_utility` for more information about data format.
`best_model`	A list containing information about parameters such as slopes, change-points, and stats such as RMSE.
`energy`	A character string. Energy Type, either 'Elec' or 'Fuel'.
`b_name`	Plot title (Building Name or Buidling ID). Defaults to an empty string.
`unretrofit_flag`	A boolean value to indicate whether it is retrofit or unretrofit. Defaults to `TRUE`. If it is retrofit, set this to `FALSE`. This only affects parameter model graph's legend labels.