Tree Like Index for single cell lineages

[ianhi]

I think the natural tree datastrcuture for single cell lineages makes much more sense as index, rather than stuffing data into datatree. Need to explore this. See below issue for more discussion

I'm also really intruiged by the idea of tree index for keeping trackign of cell lineage, and keep track of today almost always requires a separate data structure to store, when it is really metadata connected to the array

Originally posted by @ianhi in #12

[ianhi]

I think a good first pass at implementing this will be figuring out how to convert the output from this btrack script into Xarray indexes

https://github.com/quantumjot/btrack/blob/main/examples/example_tracking_pipeline-features.ipynb