Generate project.json in %TEMP% rather than in install location

With this change we generate the project.json in %temp%\getclrdbg and
restore/publish from this directory into the final install directory. This
avoids having the project.json in the final install directory.

scripts/GetClrDbg.ps1

@@ -104,13 +104,14 @@ if (-not $RuntimeID) {
 }
 Write-Host "Info: Using Runtime ID '$RuntimeID'"
 
-# create the install folder if it does not exist
-if (-not (Test-Path -Path $InstallPath -PathType Container)) {
-    New-Item -ItemType Directory -Force -Path $InstallPath
+# create the temp folder if it does not exist
+$TempPath = Join-Path -Path $env:TEMP -ChildPath "getclrdbg"
+if (-not (Test-Path -Path $TempPath -PathType Container)) {
+    New-Item -ItemType Directory -Force -Path $TempPath
 }
-$InstallPath = Resolve-Path -Path $InstallPath -ErrorAction Stop
+$TempPath = Resolve-Path -Path $TempPath -ErrorAction Stop
 
-Push-Location $InstallPath -ErrorAction Stop
+Push-Location $TempPath -ErrorAction Stop
 
 Write-Host "Info: Generating project.json"
 GenerateProjectJson $VersionNumber $RuntimeID