Improve Payment Order

[IMP] show only one wizard instead of two wizard to select invoice lines based on due date.
[IMP] improved form views.

Task Link --:

https://www.odoo.com/web#id=6020&view_type=form&model=project.task&menu_id=3942&action=327

Pad Link --:
https://pad.odoo.com/p/r.3CYovFj9kDRDM03F