Closes #10945: Enable recurring execution of scheduled reports & scripts (#11096)

* Add interval to JobResult

* Accept a recurrence interval when executing scripts & reports

* Cleaned up jobs list display

* Schedule next job only if a reference start time can be determined

* Improve validation for scheduled jobs

netbox/extras/forms/reports.py

@@ -1,4 +1,5 @@
 from django import forms
+from django.utils import timezone
 from django.utils.translation import gettext as _
 
 from utilities.forms import BootstrapMixin, DateTimePicker
@@ -15,3 +16,16 @@ class ReportForm(BootstrapMixin, forms.Form):
         label=_("Schedule at"),
         help_text=_("Schedule execution of report to a set time"),
     )
+    interval = forms.IntegerField(
+        required=False,
+        min_value=1,
+        label=_("Recurs every"),
+        help_text=_("Interval at which this report is re-run (in minutes)")
+    )
+
+    def clean_schedule_at(self):
+        scheduled_time = self.cleaned_data['schedule_at']
+        if scheduled_time and scheduled_time < timezone.now():
+            raise forms.ValidationError(_('Scheduled time must be in the future.'))
+
+        return scheduled_time