PR# 19673 Please allow chhosing non-default location for new projects

EiffelStudio's "Open project" dialog has the drop-down field "Location:"
where we can set the path where ES will create the EIFGENS folder, which
can be different from the path where the project itself resides. But the
"Create project" dialog has no such an option; the subsequent "Choose
your project name and directory" dialog has a field "Location:", but it
refers only to where the project, i.e. the .ecf and .e files will be
created, and where ES will create the EIFGENS folder by default. This
forces the user who wants to keep EIFGENS in a separate path to create
the project, close it, delete the EIFGENS folder and reopen the project
setting a new path for ES to create EIFGENS.