Add more plotting utils

[vaithak]

We need to add more functions and utilities for visualization and plotting the progress. some examples include:

• [ ] Showing the objective function for 1d problems and showing the progress
• [ ] Plotting contour map for 2d problems
• [ ] Plotting progress of y_vals, this can be done for any dimensional problem, see Harshit's notebook for reference.
• [ ] See https://github.com/ARM-software/mango, we will be implementing a similar for 2d problems.