Rewrite Icon fetching (#3023)

* Rewrite Icon fetching

* Move validation to IconUri, Uri, or UriBuilder

* `dotnet format` 🤖

* PR suggestions

* Add not null compiler hint

* Add twitter to test case

* Move Uri manipulation to UriService

* Implement MockedHttpClient

Presents better, fluent handling of message matching and response
building.

* Add redirect handling tests

* Add testing to models

* More aggressively dispose content in icon link

* Format 🤖

* Update icon lockfile

* Convert to cloned stream for HttpResponseBuilder

Content was being disposed when HttResponseMessage was being disposed.
This avoids losing our reference to our content and allows multiple
usages of the same `MockedHttpMessageResponse`

* Move services to extension

Extension is shared by testing and allows access to services from
our service tests

* Remove unused `using`

* Prefer awaiting asyncs for better exception handling

* `dotnet format` 🤖

* Await async

* Update tests to use test TLD and ip ranges

* Remove unused interfaces

* Make assignments static when possible

* Prefer invariant comparer to downcasing

* Prefer injecting interface services to implementations

* Prefer comparer set in HashSet initialization

* Allow SVG icons

* Filter out icons with unknown formats

* Seek to beginning of MemoryStream after writing it

* More appropriate to not return icon if it's invalid

* Add svg icon test

src/Icons/Util/IPAddressExtension.cs

@@ -0,0 +1,42 @@
+#nullable enable
+
+using System.Net;
+
+namespace Bit.Icons.Extensions;
+
+public static class IPAddressExtension
+{
+    public static bool IsInternal(this IPAddress ip)
+    {
+        if (IPAddress.IsLoopback(ip))
+        {
+            return true;
+        }
+
+        var ipString = ip.ToString();
+        if (ipString == "::1" || ipString == "::" || ipString.StartsWith("::ffff:"))
+        {
+            return true;
+        }
+
+        // IPv6
+        if (ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6)
+        {
+            return ipString.StartsWith("fc") || ipString.StartsWith("fd") ||
+                ipString.StartsWith("fe") || ipString.StartsWith("ff");
+        }
+
+        // IPv4
+        var bytes = ip.GetAddressBytes();
+        return (bytes[0]) switch
+        {
+            0 => true,
+            10 => true,
+            127 => true,
+            169 => bytes[1] == 254, // Cloud environments, such as AWS
+            172 => bytes[1] < 32 && bytes[1] >= 16,
+            192 => bytes[1] == 168,
+            _ => false,
+        };
+    }
+}