Rust bindings for C++ geom2graph powered by GEOS

[Notgnoshi]

Closes #130 Closes #165 Closes #92 by removing 3D WKT parsing support

• [x] geom2graph library
  • [x] flatten geoms
  • [x] create GeometryCollectionShim
  • [x] unpack GeometryCollectionShim into a geos GeometryCollection
  • [x] node the collection - use the IteratedNoder instead of SnappingNoder, and catch any exceptions
  • [x] create a c++ GeometryGraph
  • [x] wrap in a Rust GeometryGraphShim
  • [x] unpack GeometryGraphShim into Rust GeometryGraph (petgraph)
  • [x] replicate the C++ tests in Rust
  • [x] wrapper layer to hide the FFI details
• [x] graph2geom library
  • [x] Convert Rust GeometryGraph to GeometryGraphShim
  • [x] Convert GeometryGraphShim into a std::vec<Geometry*> (LineString) edges
  • [x] Polygonizer
  • [x] Pass Polygons and Dangles back to Rust side
  • [ ] Maybe write Polygonizer in Rust???
  • [x] wrapper layer to hide the FFI details
• [x] geom2graph binary
  • [x] geom2graph
  • [x] graph2geom
  • [x] test against C++ tool
  • [ ] remove C++ tool
  • [x] optionally snap the results
  • [x] edit README and examples
• [x] build the bindings in the CI pipeline
  • [x] provide Ninja / Make
  • [x] provide g++
  • [x] update geos submodule
  • [x] Remove GENERATIVE_CARGO environment variable in favor of features #165
  • [x] add --all-features
  • [x] build and run C++ tests too

[Notgnoshi]

By adding the bindings directly to generative, now every Rust tool transitively depends on liblog4cplus and libgeos

I won't fix this in this PR, but it's something to keep in mind.