Use mkdocs_graphviz instead of mdx_inline_graphviz

Closes #3333 (closed)

mdx_inline_graphviz is about 7 years old without update, and it now breaking the other default code blocks.

mkdocs-graphviz was released recently and looks to do the trick.

This MR update the documentation to use the new syntax.

This lib is new and not yet in conda. I will create an issue related to it.

Both code block and dot is working