Add macOS 10.13 to the CI

Includes provisioning scripts and modifications
to default.txt enabling the build. Builds are
disabled while fixing or blacklisting autotests.

Task-number: QTQAINFRA-1299
Task-number: QTQAINFRA-1300
Change-Id: I0fde33c8028c7ded9d07e8d9cb0dcfb03d5db188
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>

coin/provisioning/common/macos/install_xcode.sh

@@ -49,7 +49,11 @@ function InstallXCode() {
     version=$2
 
     echo "Uncompressing and installing '$sourceFile'"
-    xzcat < "$sourceFile" | (cd /Applications/ && sudo cpio -dmi)
+    if [[ $sourceFile =~ tar ]]; then
+        cd /Applications/ && sudo tar -zxf "$sourceFile"
+    else
+        xzcat < "$sourceFile" | (cd /Applications/ && sudo cpio -dmi)
+    fi
 
     echo "Accept license"
     sudo xcodebuild -license accept