## [FIX] sale_renting_planning: prevent user to do a conflict with rental shift

Before this commit, the user could update the shift linked to a rental
order and creating a conflict with another shift for the same resource
and so, it would be impossible for the resource to be in 2 spaces at the
same time (or it is impossible to rent a room to 2 different customers).

This commit returns an Validation Error if the user updates the planned dates
of a rental shift and creates a conflict.

## [FIX] sale_renting_planning: add problematic shifts only if rental order

Before this commit, the previous fix making sure the error, saying no
resource is available during the generation of a shifts when the user
confirms a sale order, is only displayed when the `Sync Shifts and
Rental Orders` is enabled, could potentially never display the error
when it should be expected because we only check if the last SOL of the
batch to generate shifts has the feature enable or not.

This commit makes sure the error is correctly displayed as expected.

## [FIX] sale_renting_planning: update condition of Rental buttons in shift

Before this commit, the user could click on Create order button for an
open shift is the role having the rental feature enabled. To problem is
a resource is required to make sure the rental order can be delivered.
About the other button shown, `Add to Last Order` one, this one could be
clicked even if the shift is in conflict with another shift and so, it
will display a warning saying no resource is available.

This commit makes sure
- `Create Order` button in shift form view is not
visible when the shift is a open shift.
- `Create Order` and `Add to Last Order` buttons in shift form view are
not displayed when the shift is in conflict.

task-5065930