Refactor grid_visualizer and get upstream

After the [`utils/grid_visualizer`](https://github.com/antmicro/symbiflow-arch-defs/tree/grid_visualizer/utils/grid_visualizer) is landed in #679 there are a couple of improvements that could be made.

- [ ] Refactor tool into a "base tool" and the "symbiflow-arch-defs tool". The "base tool" should be useful for any VtR architecture.xml file.
- [ ] Improve the output rendering to be even prettier.
- [ ] Get the "base tool" into the upstream VtR repository.

Things which are specific to "symbiflow-arch-defs";
* ROI highlighting
* conn-db functionality

Things which should be useful to any vpr user;
* arch XML rendering.
* rr_graph XML rendering.