Add function to plot waterbodies colored by the last_valid_obs column.

[vikineema]

Proposed changes

Add function to plot waterbodies colored by the last_valid_obs column.

Checklist (replace [ ] with [x] to check off)

• Remove any unused Python packages from Load packages
• Remove any unused/empty code cells
• Remove any guidance cells (e.g. General advice)
• Ensure that all code cells follow the PEP8 standard for code. The jupyterlab_code_formatter tool can be used to format code cells to a consistent style: select each code cell, then click Edit and then one of the Apply X Formatter options (YAPF or Black are recommended)
• Include relevant tags in the first notebook cell and re-use tags if possible
• Ensure appropriate colour schemes have been used to maximise accessibility for vision impairment. Test your images or learn more with Coblis or TPGI
• Clear all outputs, run notebook from start to finish, and save the notebook in the state where all cells have been sequentially evaluated

Closes issues (optional)

• Closes Issue #000

[lisarebelo]

Thanks Vicky, looks good.