Add file extensions from MSVS to gitignore file

Change-Id: Icb976111a3442eff2cd3ba0b015eef7067fe7006
Reviewed-on: https://gerrit.libreoffice.org/7582
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>