templates/origin-save: Add a new "Info" column in save requests table

An "Info" button has been added in that new column. When clicking on it, a
popover containing various loading task information will be displayed.

For anonymous users, the displayed info are:

• Task type
• Task arguments
• Task scheduling date
• Task start date
• Task termination date
• Task duration
• Task log (with Traceback removed in case of failed task, only the exception is displayed)

For staff users, more internal info and a full traceback are displayed in
case of a failed task.

Related to T2325