Extract function to pull df of node annotations for treeview

[russHyde]

This relates to trimming the tooltip text for tree views.
Several internal nodes had undefined cluster IDs when the data for scanner-env-2022-08-01.rds was presented in tfpbrowser.
To simplify debugging where those missing (NA) cluster IDs were defined, we extracted a function that defines the data that annotates the nodes in a tree plot away from treeview().

This removes a few temporary variables from inside treeview() (sc2, tdvars, td0, td1).

(By the way, the internal nodes that end up with NA cluster IDs all derive from the temporary 'x' variable that is generated in the "# internal" section where td1 is defined; I'm currently a bit stuck working out how to map these tree-node IDs to cluster IDs)

[jr-nicola]

I'm currently a bit stuck working out how to map these tree-node IDs to cluster IDs)

Do any of the nodes have a tree-node ID and a cluster ID, and if there ever a case where the same number is used for a cluster ID and a tree-node ID?

I'm wondering if the tree node ID should be used instead of the cluster ID in the cases where there is no cluster ID. Do you have a couple of examples of tree-node numbers and we can look to see if there's a folder with that number?

Would it be possible to export the labelling data somehow, with the node number from ggplot and the clusterID - to call that directly in tfpbrowser, instead of trying to parse the tooltips again?

[russHyde]

I can have a look, but, the tree node IDs are an integer sequence (1:x for the x leaves, x+1 : x+y for the y internal nodes). My understanding is this node ID is just for internal representation and doesn't relate to something important within the dataset.