Feat: support new fields for meeting mode, proposed start date and duration.

As per title

app/forms/project.py

@@ -49,10 +49,8 @@ class ProjectForm(FlaskForm):
             )
 
     def validate_duration(self, field):
-        if (
-            field == self.duration_in_weeks
-            and field.data is not None
-            and field.data < 0
+        if all(
+            (field == self.duration_in_weeks, field.data is not None, field.data < 0)
         ):
             self.meeting_mode.errors += "Invalid duration."
             raise ValidationError(