Add file for strong naming assembly

If you use `sn -T` on the version 1.3.0 RabbitMQ dll, you get this:

```
lib\net6.0> sn -T .\RabbitMQ.Stream.Client.dll

Microsoft (R) .NET Framework Strong Name Utility  Version 4.0.30319.0
Copyright (c) Microsoft Corporation.  All rights reserved.

.\RabbitMQ.Stream.Client.dll does not represent a strongly named assembly
```

Actually do the signing correctly. Thanks for double-checking @Zerpet

Author: lukebakken

RabbitMQ.Stream.Client/RabbitMQ.Stream.Client.csproj

@@ -16,6 +16,7 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <PackageOutputPath>..\packages</PackageOutputPath>
     <RootNamespace>RabbitMQ.Stream.Client</RootNamespace>
+    <SignAssembly>True</SignAssembly>
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
     <Title>RabbitMQ Stream Client Library for .NET</Title>
   </PropertyGroup>
@@ -27,8 +28,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
-    <_Parameter1>Tests</_Parameter1>
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+    <_Parameter1>Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100e5f75a5f3e8c9cf8151b55c3460da0f58823b3139dd0672f7aae5d875416c363cfdbee2d98a09ee53157213447a128893225a56871be16aba8aa57ac7ceb7824f03131c7c9028a8050660652b26ab7568eaeebf022948e496e00e35e01e5f56d67351278ec90b6c0bfc965610281e7bdf25b0c9e625fdde89f2ed5f3f5757bbc</_Parameter1>
     </AssemblyAttribute>
   </ItemGroup>
 

Tests/Tests.csproj

@@ -1,8 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
+    <AssemblyOriginatorKeyFile>../rabbit.snk</AssemblyOriginatorKeyFile>
     <IsPackable>false</IsPackable>
     <MinVerSkip>true</MinVerSkip>
+    <SignAssembly>True</SignAssembly>
   </PropertyGroup>
 
   <ItemGroup>