Network check fixes

- Proper network mapping
- Proper reclass lookup
- VIP detection
- Simple error gathering
- IP shown as 'exploded', i.e. in CIDR format
- MTU matching and detection
- Errors class for handling errors, including codes and indices
- Summary and detailed errors view
- Flake8 refactoring

Change-Id: I8ee37d345bdc21c7ad930bf8305acd28f8c121c8
Related-PROD: PROD-28199
diff --git a/cfg_checker/modules/reclass/comparer.py b/cfg_checker/modules/reclass/comparer.py
index b0b7b37..6591d16 100644
--- a/cfg_checker/modules/reclass/comparer.py
+++ b/cfg_checker/modules/reclass/comparer.py
@@ -4,13 +4,14 @@
 """
 import itertools
 import os
+
+from cfg_checker.common import logger, logger_cli
+from cfg_checker.reports import reporter
+
 import yaml
 
-from cfg_checker.reports import reporter
-from cfg_checker.common import logger, logger_cli
 
-
-def get_element(element_path, input_data):     
+def get_element(element_path, input_data):
     paths = element_path.split(":")
     data = input_data
     for i in range(0, len(paths)):
@@ -18,7 +19,7 @@
     return data
 
 
-def pop_element(element_path, input_data):     
+def pop_element(element_path, input_data):
     paths = element_path.split(":")
     data = input_data
     # Search for last dict
@@ -38,7 +39,7 @@
         "03_cluster": "classes:cluster",
         "04_other": "classes"
     }
-    
+
     models = {}
     models_path = "/srv/salt/reclass"
     model_name_1 = "source"
@@ -123,7 +124,7 @@
             # creating dict structure out of folder list. Pure python magic
             parent = reduce(dict.get, folders[:-1], raw_tree)
             parent[folders[-1]] = subdir
-        
+
         self.models[name] = {}
         # Brake in according to pathes
         _parts = self._model_parts.keys()
@@ -133,7 +134,7 @@
                 self._model_parts[_parts[ii]],
                 raw_tree[root_key]
             )
-        
+
         # save it as a single data object
         self.models[name]["rc_diffs"] = raw_tree[root_key]
         return True
@@ -223,8 +224,7 @@
                     if _removed or _added:
                         _removed_str_lst = ["- {}".format(item)
                                             for item in _removed]
-                        _added_str_lst = ["+ {}".format(item)
-                                            for item in _added]
+                        _added_str_lst = ["+ {}".format(i) for i in _added]
                         _report[_new_path] = {
                             "type": "list",
                             "raw_values": [
@@ -287,7 +287,6 @@
                         ))
         return _report
 
-
     def generate_model_report_tree(self):
         """Use two loaded models to generate comparison table with
         values are groupped by YAML files