don't treat all geometry collections as points/lines when noding

[uclaros]

Description

When a GEOMETRYCOLLECTION is passed into QgsGeos::nodeGeometries() it was treated as a point or line geometry, potentially causing a crash later when splitting.
Now it will trigger a geos exception with an error message IllegalArgumentException: Operation not supported by GeometryCollection\n which is caught.
We should probably not allow splitting of geometry collections in the first place and inform the users about their messed up data, but at first let's avoid crashing.

Fixes #58379

[nyalldawson]

Wouldn't it be better to iterate over the collection parts and node each in turn? The result should be usable -- if it's a valid geometry then none of the parts will overlap and potentially affect the noding solution.

[github-actions]

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[uclaros]

Wouldn't it be better to iterate over the collection parts and node each in turn? The result should be usable -- if it's a valid geometry then none of the parts will overlap and potentially affect the noding solution.

For that we would need to first make sure it is a homogeneous collection, ie not mixing lines and polygons, however in that case it would have been a multipolygon/multilinestring instead.
Properly splitting a mixed collection of lines and polygons would require non trivial changes to the splitting logic and will have several edge cases to handle, like what happens if line splitting and polygon splitting have different operation results?

[nyalldawson]

@uclaros ah sorry, I'd mistaken this method for one which just returns the GEOS noded geometry alone -- but that's QgsGeos::node. Please ignore!