Add userTips feature flag (#1011)

Task/Issue URL:
https://app.asana.com/0/72649045549333/1208381891916914/f
iOS PR:  duckduckgo/iOS#3416
macOS PR:  duckduckgo/macos-browser#3365
What kind of version bump will this require?: Minor

**Description**:
Add userTips feature flag

Sources/BrowserServicesKit/PrivacyConfig/Features/PrivacyFeature.swift

@@ -59,6 +59,7 @@ public enum PrivacyFeature: String {
     case autofillSurveys
     case marketplaceAdPostback
     case autocompleteTabs
+    case networkProtection
 }
 
 /// An abstraction to be implemented by any "subfeature" of a given `PrivacyConfiguration` feature.
@@ -95,6 +96,16 @@ public enum DBPSubfeature: String, Equatable, PrivacySubfeature {
     case freemium
 }
 
+public enum NetworkProtectionSubfeature: String, Equatable, PrivacySubfeature {
+    public var parent: PrivacyFeature {
+        .networkProtection
+    }
+
+    /// Display user tips for Network Protection
+    /// https://app.asana.com/0/72649045549333/1208231259093710/f
+    case userTips
+}
+
 public enum SyncSubfeature: String, PrivacySubfeature {
     public var parent: PrivacyFeature {
         .sync