[IMP] sale_timesheet: wizard to create SO from project

This commit provides a wizard to create a SO from
a non billable project. It sets sale_line_id on the
project, and the project on the SO line to simulate
the project was created by the SOL.
The created SO contains one line with a selected
service product, with ordered qty set as the total
of planned hours of all task in projects.
The wizard also links all non billable active
tasks of the project to the SO line (and its
timesheet entries).