Occviz Upgrade and Get Occultation Paths endpoint (#1066)

* perf(occviz.py): improves performance and fix some errors

this is a major change, nevertheless keeps backwards compatibility

* feat(occultation.py): adds a new endpoint to get the shaddow paths of an occultation get_occultation_paths

* fix(lint): lint fix

* fix(occviz): extreme conditions in the filter were fixed

backend/common/views.py

@@ -32,7 +32,7 @@ def teste(request):
         rows = []
         ids = []
         for e in events:
-            is_visible, info = visibility_from_coeff(
+            is_visible = visibility_from_coeff(
                 latitude=float(lat),
                 longitude=float(long),
                 radius=float(radius),