Halt at each step of splitting algorithm for intermediate product inspection

[spwoodcock]

Is your feature request related to a problem? Please describe.

• Primarily an enhancement for devs / power users, but I'm sure the average user might also appreciate to see all these intermediate steps.
• Each step tends to dump into a separate table, so it would be pretty each to export as GeoJSON for visualisation.

Describe the solution you'd like

• Related to Create Web Component for fmtm-splitter steps #66
• We have two modes:
  • One step: input AOI --> click --> output tasks (magic approach).
  • Multi step: input AOI --> click through each step seeing intermediate geometries --> output tasks (inspection / detailed approach).
• Each step should also allow download of a GeoJSON for viewing elsewhere.