Make Builds Run in Parallel (JeanPhilippeKernel#509)

- Use CMake's `--parallel` flag to allow MSVC based builds to work in
  parallel.
- Ninja on Linux works in parallel by default and that is why its CI
  works alot faster.

Author: MathewBensonCode

Scripts/BuildEngine.ps1

@@ -140,7 +140,9 @@ function Build([string]$configuration, [int]$VsVersion , [bool]$runBuild) {
 
         Write-Host "Building $systemName $architecture $configuration"
 
-        $buildArguments = "--build --preset $configName"
+        $processorCount = [ENVIRONMENT]::ProcessorCount
+
+        $buildArguments = "--build --preset $configName --parallel $processorCount"
 
         $buildProcess = Start-Process $cMakeProgram -ArgumentList $buildArguments -NoNewWindow -PassThru