(chocolatey#3286) Prevent MSI Upgrades

Currently it's not possible to upgrade Chocolatey with the MSI. This
commit adds functionality to the MSI that will error instead of blindly
allowing an upgrade that doesn't do anything.

src/chocolatey.install/chocolatey.en-us.wxl

@@ -5,5 +5,6 @@
     <String Id="ProfileAdditionDescription" Overridable="yes">Add the Chocolatey Helpers to your PowerShell Profile to enable tab-completions.
 Defaults to adding to the AllUsersAllHosts profile.</String>
     <String Id="RequiresDotNet48" Overridable="yes">This application requires .NET Framework 4.8. Please install the .NET Framework then run this installer again.</String>
+    <String Id="UpgradeNotAllowed" Overridable="yes">UPGRADE FAILURE: Chocolatey CLI cannot be upgraded via the MSI. Please run 'choco upgrade chocolatey' from an elevated terminal window.</String>
     <String Id="ToolsFolderDescription" Overridable="yes">Sets the location for the Tools Folder</String>
-</WixLocalization>
+</WixLocalization>

src/chocolatey.install/chocolatey.wxs

@@ -11,7 +11,7 @@
 
   <Product Name="$(var.ProductName)" Id="*" UpgradeCode="$(var.ProductCode)" Language="1033" Manufacturer="$(var.ProductVendor)" Codepage="1252" Version="$(var.ProductVersion)">
     <Package Id='*' Platform='x86' Keywords='Installer' Description="$(var.ProductName)" Comments="$(var.ProductSummary)" InstallScope="perMachine" InstallerVersion="200" Compressed="yes" />
-    <MajorUpgrade Schedule="afterInstallInitialize" DowngradeErrorMessage="!(loc.NewerVersionInstalled)" />
+    <MajorUpgrade Schedule="afterInstallInitialize" DowngradeErrorMessage="!(loc.NewerVersionInstalled)" Disallow="yes" DisallowUpgradeErrorMessage="!(loc.UpgradeNotAllowed)" />
     <Media Id="1" Cabinet="$(var.ArtifactName).cab" EmbedCab="yes" />
 
     <!-- Installation Properties -->