Improve LSIF root boundaries
Created by: efritz
Specifically for detection of overlapping dumps, we may treat the following as conflicting:
alpha/bravo/charliealpha/bravo/charliefoxtrot
Because one is a prefix of the other, even though one path does not subsume the other. This may also be an issue in finding roots for closest dumps.
We could simply require that all roots end with a normalized separator to fix this issue.