[sourcemaps] Improve ignore-listing performance (#81311)
This improves performance of finding the relevant section in Index Source Maps by using binary search (O(N) -> O(log N)).
This allows us to improve the performance of the fast path for checking if a source is ignore-listed in Index Source Maps:
Instead of checking if every section in Index Source Maps ignores everything, we just find the relevant section (now O(log N) instead of O(N)) and check if that section ignores everything.
