Dependency update / fixes / skrungle bungle (#23745)

* Give .props files 2-space indents.

* Move to Central Package Management.

Allows us to store NuGet package versions all in one place. Yay!

* Update NuGet packages and fix code for changes.

Notable:

Changes to ILVerify.
Npgsql doesn't need hacks for inet anymore, now we need hacks to make the old code work with this new reality.
NUnit's analyzers are already complaining and I didn't even update it to 4.x yet.
TerraFX changed to GetLastSystemError so error handling had to be changed.
Buncha APIs have more NRT annotations.

* Remove dotnet-eng NuGet package source.

I genuinely don't know what this was for, and Central Package Management starts throwing warnings about it, so YEET.

* Remove Robust.Physics project.

Never used.

* Remove erroneous NVorbis reference.

Should be VorbisPizza and otherwise wasn't used.

* Sandbox fixes

* Remove unused unit test package references.

Castle.Core and NUnit.ConsoleRunner.

* Update NUnit to 4.0.1

This requires replacing all the old assertion methods because they removed them 🥲

* Oh so that's what dotnet-eng was used for. Yeah ok that makes sense.

* Add Robust.Analyzers.Test

* Update submodule

* commit to re-run CI

Content.Server/IP/IPAddressExt.cs

@@ -1,11 +1,34 @@
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Net;
 using System.Net.Sockets;
+using NpgsqlTypes;
 
 namespace Content.Server.IP
 {
     public static class IPAddressExt
     {
+        // Npgsql used to map inet types as a tuple like this.
+        // I'm upgrading the dependencies and I don't wanna rewrite a bunch of DB code, so a few helpers it shall be.
+        [return: NotNullIfNotNull(nameof(tuple))]
+        public static NpgsqlInet? ToNpgsqlInet(this (IPAddress, int)? tuple)
+        {
+            if (tuple == null)
+                return null;
+
+            return new NpgsqlInet(tuple.Value.Item1, (byte) tuple.Value.Item2);
+        }
+
+        [return: NotNullIfNotNull(nameof(inet))]
+        public static (IPAddress, int)? ToTuple(this NpgsqlInet? inet)
+        {
+            if (inet == null)
+                return null;
+
+            return (inet.Value.Address, inet.Value.Netmask);
+        }
+
         // Taken from https://stackoverflow.com/a/56461160/4678631
         public static bool IsInSubnet(this System.Net.IPAddress address, string subnetMask)
         {