Purpose of this PR to improve the generic usage of project app
So in this commit done the following changes:
- when a project is archived, the 'tasks' stat button should
count/show archived tasks
- when delete project it's milestone should also be deleted automatically.
- project.task > blocked by notebook: it should be possible to select tasks
in projects that are not allowing 'task dependencies'
- project.task portal form view: hide the description if it is empty
task-2853991
closesodoo/odoo#94138
Related: odoo/enterprise#28654
Signed-off-by: Laurent Stukkens (ltu) <ltu@odoo.com>