Using backward search in freespace planning algorithm

[alanmengg]

When using autoware.universe parking module in simulation and test in real scene, one problem is that ego vehicle final pose doesn't fit goal well.
Because current algorithm is forward search, the cost only consider path so far and reedssheep heuristic may not find future path for easy control( in our test). To overcome the issue, we thought backward search can be used so that near goal trajectory can be well execute.
Would it be considered implement along with forward search in future?