We currently rely on GEOS for writing and reading WKT, which requires an unnecessary copy and allocation step to convert back and forth between DuckDB and GEOS geometries.

We should implement our own WKT parser/writer that can use arena allocation.

Since we also only support of a subset of WKT (no extended WKT) this would also give us more control and ensure we don't accidentally import geometries we can't support - basically throw at the parsing step.