Follow-up to https://github.com/discourse/discourse/pull/31271
In the linked PR, we made `<GroupChooser />` use the site's preloaded
list of groups instead of fetching the list from the servers every time
the component is triggered. However, when a site has thousands of
groups, the performance issue has shifted from the server to the browser
— `<GroupChooser />` takes several seconds to render in the browser for
a site with thousands of groups and the sites becomes completely
unresponsive while the component is rendering.
This PR changes the `<GroupChooser />` so it limits the displayed groups
to 100, with ability to filter the list to show more groups when there
are more than 100 groups.
