Display backup destination validation details

[DavidePrincipi]

The validation of a backup destination may fail for many reasons. Some of them are correctly handled and reported to the user. In some cases the error reason is reported in the toast notification detailed info, which is difficult for the user to see because the form is displayed as a modal and the notification is behind the modal layer.

This is the current generic error message

Proposal, change the generic error message, to invite viewing the error details in the toast notification.

In a similar scenario in TLS Certificates page for unknown errors we wrote:

Check 'Request certificate' error in the notification drawer for details

Note: the current generic message still uses the old "repository" name in the warning. It should use the word "destination" instead.

Refs https://community.nethserver.org/t/backup-to-samba-share-on-ns8/24787/7?u=davidep

Thanks MadPatrick

[stephdl]

QA

use test version core:3.9.1-dev.1

When you fail to add or edit a backup repository you display banner with a button that open the notification drawer to inform what is occurring and why you failed by clicking after on the notification

[mrmarkuz]

Test case verified

• The new error message is shown including a button to go to the notification drawer