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

konova/forms.py

@@ -71,6 +71,19 @@ class BaseForm(forms.Form):
         """
         self.fields[field].initial = val
 
+    def add_placeholder_for_field(self, field: str, val):
+        """
+        Adds a placeholder to a field after initialization
+
+        Args:
+            field (str): Field name
+            val (str): Placeholder
+
+        Returns:
+
+        """
+        self.fields[field].widget.attrs["placeholder"] = val
+
     def load_initial_data(self, form_data: dict, disabled_fields: list):
         """ Initializes form data from instance
 
@@ -369,7 +382,7 @@ class RecordForm(BaseModalForm):
 
         """
         super_val = super().is_valid()
-        msgs = self.instance.quality_check()
+        msgs = self.instance.quality_check() or []
         for msg in msgs:
             self.add_error(
                 "confirm",