Make group picker case insensitive for /rest/api/3/groups/picker

Summary

When using /rest/api/3/groups/picker it would be great if queries are treated case insensitive

Background

Vendor raised feature request in DEVHELP with the following use case and notes:

"query~admin" or "query~Admin" doesn't work at all. It is just ignored.

I discovered another thing, though. I have a group "site-admins".
When I search with rest/api/3/groups/picker?query=Site-Admins it returns this group.
When I search with rest/api/3/groups/picker?query=site-admins it returns this group.
When I search with rest/api/3/groups/picker?query=site-adm it returns this group.
When I search with rest/api/3/groups/picker?query=Site-Adm it returns nothing.
So the search seems to be case insensitive only when I provide the full name of a group.

A use case:
We have a filter option in our apps to search groups. When searching for a group in the input, the search is case sensitive. So if a user has a group named: "Developers", he can't find them by inserting e.g. "deve".