Fix very high false negative rate for insertion SVs with LRG

[adamnovak]

Calling with Long Read Giraffe gets @jmonlong a very high false negative rate for insertion SVs. We need to figure out where they went.

See https://ucsc-gi.slack.com/archives/CJ2EHEH1A/p1729633305487609

[xchang1]

@jmonlong I think I fixed this here
The problem was that when we tried to align between two nodes against the graph, we pulled out a subgraph that excluded the insertion node because the distance to go between the seeds with the insertion would be longer than the length of the read subsequence we wanted to align. I changed the distance limit we can walk through to find the subgraph to include the length of the longest gap we allow