Feature request: repo.tree() to visualize ancestry

[rabernat]

I frequently find myself wanting to visualize the tree of icechunk snapshots, branches, tags, etc. Like this wonderful figures.

It would be amazing if we could render a text-based snapshot tree or even generate the mermaid.js code directly!

We might not want to explicitly list every snapshot if there are many, just the branches, tags, etc, with some placeholder in between ("1000 snapshots").

[bendichter]

I would love an interactive HTML version of this that would render in a jupyter notebook!