feat(ip-filter): add CIDR overlap detection, normalization, and full XML docs

- Added `ContainsIp` method to check if a single IP belongs to any registered subnet
- Added `ContainsCidr` method to detect CIDR membership and overlaps
- Added `NormalizeCidr` to normalize IP/CIDR to the correct network address
- Added `FindOverlaps` to collect all overlapping subnets for IPs or CIDRs
- Implemented helper traversals for subtree searching in Patricia Trie
- Added XML `<summary>` docs and inline comments for GitHub-ready documentation
- Improved readability and maintainability for future contributors

Author: Peykami

samples/Samples/Program.cs

@@ -2,6 +2,31 @@
 
 using Arad.TrieNet;
 
+(string cidr, string? username, bool isDeny)[] initial =
+[
+    ("91.199.9.60", "user1", false),
+    ("185.37.54.112/27", "user1", false),
+    ("180.31.2.5/29", "user2", false),
+    ("fe80::/10", "user2", false),
+    ("10.0.0.0/5", "user3", false),
+    ("2001:db8::/32", "user3", false),
+    ("192.168.1.0/24", null, true),
+    ("0.0.0.0/0", "admin", false),
+    ("192.168.1.1-192.168.1.10", "user1", false)
+];
+
+foreach ((string cidrItem, string? username, bool isDeny) in initial)
+{
+    if (isDeny)
+    {
+        IPFilter.AddDeny(cidrItem.AsSpan());
+    }
+    else
+    {
+        IPFilter.AddNetwork(cidrItem.AsSpan(), username!);
+    }
+}
+
 Console.WriteLine("IPFilter tests:");
 Console.WriteLine("IsAllowed:");
 (bool allowed, string reason) = IPFilter.IsAllowed("user1", "185.37.54.116");