wpf: strong-name sign Microsoft.Terminal.Wpf (#18836)

This requires us to delay-sign the assembly with a public key (the snk
file), and then later submit it for strong naming. This is separate from
code signing, and has to take place before it.

The snk file does not contain any private key material.

This cannot merge until we are approved to use this new signing "key
code".

.github/actions/spelling/expect/expect.txt

@@ -1679,6 +1679,7 @@ SMARTQUOTE
 SMTO
 snapcx
 snapcy
+snk
 SOLIDBOX
 Solutiondir
 somefile

build/config/esrp.build.batch.wpfdotnet.json

@@ -6,6 +6,20 @@
         ],
         "SigningInfo": {
             "Operations": [
+                {
+                    "KeyCode": "CP-233904-SN",
+                    "OperationSetCode": "StrongNameSign",
+                    "ToolName": "sign",
+                    "ToolVersion": "1.0",
+                    "Parameters": []
+                },
+                {
+                    "KeyCode": "CP-233904-SN",
+                    "OperationSetCode": "StrongNameVerify",
+                    "ToolName": "sign",
+                    "ToolVersion": "1.0",
+                    "Parameters": []
+                },
                 {
                     "KeyCode": "CP-230012",
                     "OperationSetCode": "SigntoolSign",

src/cascadia/WpfTerminalControl/WpfTerminalControl.csproj

@@ -15,6 +15,12 @@
     <Version>0.1</Version>
   </PropertyGroup>
   
+  <PropertyGroup Condition="'$(WindowsTerminalOfficialBuild)'=='true'">
+    <SignAssembly>true</SignAssembly>
+    <DelaySign>true</DelaySign>
+    <AssemblyOriginatorKeyFile>..\..\..\build\config\272MSSharedLibSN2048.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
+
   <ItemGroup>
     <AdditionalFiles Include="$(MSBuildThisFileDirectory)stylecop.json">
       <Visible>true</Visible>