Rename partitions when swapping partitioned tables

What does this MR do?

Related to #241267 (closed)

In !44655 (merged), a migration helper was added that implements the final step of a partitioning migration: swapping the original non-partitioned table with the partitioned copy. The swap is accomplished by transactionally renaming the two tables (as well as some other dependent objects).

This MR builds on that change by also renaming all the partitions associated with the partitioned table, so their names match the new naming schema of the parent table. As part of that renaming process, the primary key is also renamed, since by default the primary key name is "#{table_name}_pkey".

For example, if a partitioned table of audit_events_part is renamed to simply audit_events:

• rename a partition with name audit_events_part_202001 to audit_events_202001
• rename that same partition primary key from audit_events_part_202001_pkey to audit_events_202001_pkey

Does this MR meet the acceptance criteria?

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