MM-25263 Add group members to search and get users and create getGroupStats endpoint (#14733)

Add tests for SearchInGroup

store/sqlstore/user_store.go

@@ -1240,6 +1240,15 @@ func (us SqlUserStore) SearchInChannel(channelId string, term string, options *m
 	return us.performSearch(query, term, options)
 }
 
+func (us SqlUserStore) SearchInGroup(groupID string, term string, options *model.UserSearchOptions) ([]*model.User, *model.AppError) {
+	query := us.usersQuery.
+		Join("GroupMembers gm ON ( gm.UserId = u.Id AND gm.GroupId = ? )", groupID).
+		OrderBy("Username ASC").
+		Limit(uint64(options.Limit))
+
+	return us.performSearch(query, term, options)
+}
+
 var spaceFulltextSearchChar = []string{
 	"<",
 	">",