ENH: use simpler boundBox handling

- use default initialize boundBox instead of invertedBox
- reset() instead of assigning from invertedBox
- extend (three parameter version) and grow method
- inflate(Random) instead of extend + re-assigning

applications/utilities/surface/surfaceHookUp/surfaceHookUp.C

@@ -178,12 +178,9 @@ void createBoundaryEdgeTrees
         // geometry there are less face/edge aligned items.
         treeBoundBox bb
         (
-            treeBoundBox(UList<point>(surf.localPoints())).extend(rndGen, 1e-4)
+            treeBoundBox(surf.localPoints()).extend(rndGen, 1e-4, ROOTVSMALL)
         );
 
-        bb.min() -= point::uniform(ROOTVSMALL);
-        bb.max() += point::uniform(ROOTVSMALL);
-
         bEdgeTrees.set
         (
             surfI,