feat: [OverlapConsolidator] add optional delta

This adds functionality that permits nearby Features to be considered
overlapping, in addition to Features which actual overlap

@see utils.py::Feature

pipeline/consolidators.py

@@ -35,11 +35,18 @@ class OverlapConsolidator(Consolidator):
     An overlap is defined as two features that share a common interval of time,ie:
       interval1.end < interval2.start or
       interval2.start < interval1.end
+
+    An optional delta parameter can be provided to allow for a 'fudge factor' in the comparison,
+    this is used to allow for small gaps between features to be considered as overlapping.
     """
 
+    def __init__(self, features: list=[], delta: float=0.0):
+        super().__init__(features)
+        self.delta = delta
+
     def consolidate(self):
         """Consolidate overlapping features"""
-        # sort features by start time
+        # sort features by start time ascending
         self.features.sort(key=lambda x: x.interval.start)
 
         # merge overlapping features
@@ -47,13 +54,13 @@ class OverlapConsolidator(Consolidator):
         consolidated = []
         current = self.features[0]
         for feature in self.features[1:]:
-            if current.interval.end < feature.interval.start:
+            if current.interval.end + self.delta < feature.interval.start - self.delta:
                 # no overlap
                 consolidated.append(current)
                 current = feature
             else:
                 # overlap
-                current.interval.end = max(current.interval.end, feature.interval.end)
+                current.interval.move_end(max(current.interval.end, feature.interval.end))
         consolidated.append(current)
 
         self.features = consolidated