StandardBranchCollisionDetector memory footprint enhancement

[AlexanderYastrebov]

Hi all.
Currently StandardBranchCollisionDetector saves all found paths in internal map (returnedPaths.add):

neo4j/community/kernel/src/main/java/org/neo4j/kernel/StandardBranchCollisionDetector.java

Line 74 in fbf4911

if ( returnedPaths.add( path ) && includePath( path, startPath, endPath ) )

On the other hand BidirectionalTraverserIterator may filter out many of them (and filters out most of them in case of Uniqueness.NODE_PATH i.e. AllSimplePaths):

neo4j/community/kernel/src/main/java/org/neo4j/kernel/impl/traversal/BidirectionalTraverserIterator.java

Line 168 in fbf4911

foundPaths = uniquenessFiltered( pathCollisions.iterator() );

The proposal is to pass Uniqueness(BidirectionalUniquenessFilter) to StandardBranchCollisionDetector so it could filter out paths before adding them to its map which leads to great memory/GC saving.

[spacecowboy]

Fixed by #4865