Do not run forward heuristic to calculate LAT, it is calculated from data already

[hannesj]

Summary

Currently we run a forward heuristic search, if either EDT or LAT is not defined in the request. In #3664, we changed the behaviour, so that the reverse heuristic doesn't require the LAT to be set anymore. However, we missed changing the criteria of when the search should be done. This PR changes that, so that LAT is not required anymore when the reverse heuristic search is done. Also the RangeRaptorDynamicSearch is fixed, as it previously expected the first search to always be the forward heuristic search.

[hannesj]

Norway (not as big change, as both EDT and LAT are defined on most searches):

Before:
Total:  
 ==> mc_destination : [  541,  499,  494,  498 ] Avg: 508.0  (σ=19.1)

After: 
Total:  
 ==> mc_destination : [  487,  445,  450,  442 ] Avg: 456.0  (σ=18.1)

Baden-Württemberg:

Before:
Total:  
 ==> mc_destination : [  628,  625,  625,  624 ] Avg: 625.5  (σ=1.5)

After:
Total:  
 ==> mc_destination : [  396,  385,  385,  385 ] Avg: 387.8  (σ=4.8)

Germany:

Before:
Total:  
 ==> mc_destination : [ 5777 ] Avg: 5777.0  (σ=0.0)

After:
Total:  
 ==> mc_destination : [ 3852 ] Avg: 3852.0  (σ=0.0)

[leonardehrenfried]

🍾