Implement multi-user search with a delimiter like comma(,)

[Sai-Deekshith-06]

It would support multi-user search by accepting a list of usernames separated by a comma (,).

• Makes easier to compare multiple users at once.
• Saves time for multiple searches individually.
• Useful for contest analysis for group comparisons.

[baoliay2008]

thanks for opening this issue, this is a great feature to be implemented.

I've designed a similar feature for easier querying multiple users which may be slightly different than this one, kindly leave this issue open and I would update it later.