[IMP] stock(_*): set optional field to simplify the tree view

* = stock_account, stock_picking_batch, stock_product_expiry, delivery

Purpose of the commit is to set the new attribute OPTIONAL = SHOW/Hide on tree
view so the user can easily hide/show the optional fields on the tree view.

Update string date field from incoming products tree view.

Update string virtual_available field from product tree view.

task-1997453
Closes #33888