Update client-side testing document for PPI-related changes

[dondi]

Upcoming v7.2.0 consists mostly of bug fixes but there are some functional changes due to broadened PPI support. These should be reflected in the latest client-side testing JSON and document

[ntran18]

I just checked the client-side testing JSON and document. It seems like the document didn't cover the difference between PPI and GRN for node coloring. So I feel like we can keep it for now, and don't need to adjust.

[dondi]

@ntran18 will review the .json files in GRNsight-archive to add test cases involving the GRN/PPI network mode plus other recently revised features that may vary based on whether the network being opened/viewed is a GRN or PPI

[ntran18]

Made changes for Client Side testing document