Partitioning Tooling: Add helper for finding duplicate index definitions
In order to rename indexes between tables, which is needed when migrating a table to be it's own first partition, we need to match indexes by their definitions.
This does not work when there are duplicate indexes, same definition, different names.
We need to add a helper that finds duplicate indexes so we can drop them in a migration, prevent adding them in future, and prevent index renaming when a duplicate condition exists.
Edited by Matt Kasa