In-app awareness of Registration Features - Group access by IP address

What does this MR do and why?

Related to #341949 (closed)

To increase discoverability for the features that can be enabled with Registration features, we'll be presenting in-app messages/hints. In this case, for setting allowed IP addresses.

Criteria to show the CTA

The offer shouldn't be presented to licensed instances because they already have the paid features available, so the callout (to enable features they already have) doesn't make sense. The decision on whether to show the offer is on the true/false of whether Service Ping is enabled, not on whether Registration Features is enabled.

Instance Type	License Type	Service Ping Setting	Expected Behavior
CE	Unlicensed	Off	Link to docs
EE	Unlicensed	Off	Link to admin setting
EE	Licensed	Off	Do not present offer
CE	Unlicensed	On	Do not present offer
EE	Unlicensed	On	Do not present offer
EE	Licensed	On	Do not present offer

Screenshots or screen recordings

Enabled feature for reference

---

When Service Ping is disabled

The CTA is always hidden if Service Ping is enabled.

Before (hidden)	After (CE)	After (EE)

How to set up and validate locally

1. Optionally restart gdk as FOSS (FOSS_ONLY=1 gdk restart) to test like a CE instance.
2. Go to any group’s Settings > General page. and expand the Permissions, LFS, 2FA section.
3. Scroll to the Allow access to the following IP addresses section.
4. Toggle a local license/subscription and/or service ping/registration features.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

app/views/groups/settings/_ip_restriction_registration_features_cta.html.haml

+- return unless registration_features_can_be_prompted?
+
+.form-group
+  = f.label :disabled_ip_restriction_ranges, class: 'label-bold' do
+    = _('Allow access to the following IP addresses')
+  = f.text_field :disabled_ip_restriction_ranges, value: '', class: 'form-control', disabled: true
+  %span.form-text.text-muted
+    = render 'shared/registration_features_discovery_message'