[Installer] Add selection of IIS website where Myrtille will be installed

[sashaqwert]

Myrtille is now installed on the "Default Web Site". In the installer, you can choose from a list of all IIS sites. If you select a non-Default site, Myrtille should work on this site with its SSL certificate.

Currently, you have to manually implement this behavior through Internet Information Services (IIS) Manager.

Myrtille is supposed to be available at https://subdomain.example.com/Myrtille, but not at https://localhost/Myrtille

[cedrozor]

The Myrtille installer was originally designed for automatic installation, so on the default website (knowing that 90% of people use it), but indeed it might be useful to be able to choose another website