Minor enhancements

* refactors eco account rest surface calculation into designated method get_available_rest()
* refactors placeholder setter for BaseForm
* adds automatic eco account identifier generating on saving
* fixes ServerMessageImportance template tag

compensation/forms.py

@@ -67,6 +67,7 @@ class NewPaymentForm(BaseModalForm):
         self.intervention = self.instance
         self.form_title = _("Payment")
         self.form_caption = _("Add a payment for intervention '{}'").format(self.intervention.title)
+        self.add_placeholder_for_field("amount", "0,00")
 
     def save(self):
         with transaction.atomic():
@@ -110,6 +111,7 @@ class NewStateModalForm(BaseModalForm):
         super().__init__(*args, **kwargs)
         self.form_title = _("New state")
         self.form_caption = _("Insert data for the new state")
+        self.add_placeholder_for_field("surface", "0,00")
 
     def save(self, is_before_state: bool = False):
         with transaction.atomic():
@@ -286,6 +288,7 @@ class NewActionModalForm(BaseModalForm):
         super().__init__(*args, **kwargs)
         self.form_title = _("New action")
         self.form_caption = _("Insert data for the new action")
+        self.add_placeholder_for_field("amount", "0,00")
 
     def save(self):
         with transaction.atomic():