R function for s4 object

[zzxahahah]

Hi,

It is hard to preview S4 objects in vscode-r compared with Rstudio

For example, in bioinformatic research, single-cell RNA-seq Seurat object, sometimes it can be extremely big.

In Rstudio it can be previewed like this, and I wanted to emulate it.

I just add some codes in vsc.R (to read the S4 object), and change the code of session.ts to show the contents. Seurat object and its' source data dgCmatrix has been tested.

Wish this can help to deal with nested data like S4 objects.