Selective data extract clipping based on extract_type

[spwoodcock]

Describe the bug

Now clipping has been disabled, we get extracts like:

So we need clipping disabled to correctly extract polylines, but clipping should probably be enabled if the extract type is polygon or point.

Expected behavior

• We determine the data extract type either from the custom extract type selected on the frontend, or it can be extracted from the select field in the data extract config YAML.
• If the provided data extract is of type point or polygon, clip the data (useStWithin: true).
• If the provided data extract is of type polyline, do not clip the data (useStWithin: false).

Additional context

We should discuss this as a team.

Perhaps it's ok to keep polygons that are intersected by the aoi.

It doesn't look at neat, but may be useful to ensure all geoms are captured.

[spwoodcock]

Related #1219

[spwoodcock]

Update to this.

If we update the project creation to use data extracts with only the map features (i.e. no polylines), then this won't be an issue. We can revert to useStWithin: true to clipping.

Then when we download the polylines in fmtm-splitter we can specify useStWithin: false to ensure we get all necessary polylines for splitting.