Add plotly-based surface plotter (to dev)

[VictorBarnes]

pyproject.toml

• I added a few necessary python libraries to a new plotting optional dependency: kaleido is for converting a plotly figure to a static image and nbformat is for rendering plotly figures in notebooks.

plotting.py

• Renamed surfplot-based plotter from plot_surf to plot_surf_surfplot
• Added plotly-based plotter as plot_surf and helper function plot_surf_single.
• I have left a bunch of #TODOs around for suggested enhancements but just wanted to get a basic working version for now.
• I added some helper functions (fetch_trace and update_trace_type) for modifying a plotly figure after it has been generated. These are related to the #TODO on line 211 in plotting.py where we need to decide whether to name each trace such that they can be easily modified post figure generation.
• compute_roi_outlines is my initial attempt to solve the #TODO on line 263 in plotting.py but I didn't include it in plot_surf yet because I haven't tested it enough.

Tutorials

• Added plot_surf_single_hemi.ipynb and plot_surf_multi_hemi.ipynb to showcase plot_surf. I had to split these over multiple notebooks because having them all in one file exceeded git's max file size (100 MB). I also cleared the outputs before I committed so you'll have to re-run the notebooks to see the plots.