Add indexes so compactor can find candidate partitions and specific partition files quickly.
Limit number of level 0 files returned for determining candidates. This should ensure that if comapction is very backed up, it will be able to work through the backlog without evaluating the entire world.
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
Paul Dix