Fix pending members member link

What does this MR do and why?

The MR fixes the pending members member link, as we were using avatarUrl instead of the webUrl.

Screenshots or screen recordings

Before	After
N/A	N/A

How to set up and validate locally

1. Ensure you're running GDK with SAAS enabled (e.g. export GITLAB_SIMULATE_SAAS=1 gdk restart)
2. With a group with an Ultimate plan
3. Navigate to Settings > Permissions, LFS, 2FA > User Cap
4. Set the user cap limit to 1
5. Navigate to the group members
6. Add one or more members (until you are above the user cap limit set in previous step)
7. Navigate to Usage Quota from the left sidebar under Settings
8. You should see an alert that you have pending members
9. Clicking the button in the alert should navigate to a pending members page
10. Verify the links for each member will point to the user's profile

Note: if you can't see pending members, try applying the following patch (while !159132 (merged) gets merged)

diff --git a/ee/app/views/groups/usage_quotas/pending_members.html.haml b/ee/app/views/groups/usage_quotas/pending_members.html.haml
index 886a50227b30..4761b563531c 100644
--- a/ee/app/views/groups/usage_quotas/pending_members.html.haml
+++ b/ee/app/views/groups/usage_quotas/pending_members.html.haml
@@ -1,4 +1,4 @@
 - page_title s_("UsageQuota|Pending Members")
 - add_to_breadcrumbs s_('UsageQuota|Usage Quotas'), group_usage_quotas_path(@group)
 
-#js-pending-members-app{ data: { namespace_id: @group.id, namespace_name: @group.name, user_cap_set: (!@group.new_user_signups_cap.nil?).to_s } }
+#js-pending-members-app{ data: { namespace_id: @group.id, namespace_name: @group.path, user_cap_set: (!@group.new_user_signups_cap.nil?).to_s } }