Adding new notebooks, updated GUI, icons

[matamadio]

Branch pushing additional scripts and notebooks:

• New notebooks for custom hazard layer, climate indices, climate timeseries.
  • Note this are only partially modularised due to small differences in how the analysis works and existing limitations, e.g. folium preview map updated to leafmap. Optimisation and modularity could be certainly improved but I'd rather look for a final refactoring after a bit more testing and additional notebooks.
• Fixed small things in existing notebooks (a couple existing shared functions have been slightly edited)
• Updated main GUI with links to notebook GUIs
• A few additional utilities for raster processing
• Updated documentation