Remove race condition (in InstanceTypes)

Soft delete all duplicate rows with the same name except one with
the biggest value in `id` column.

Soft delete all duplicate rows with the same flavorid except one with
the biggest value in `id` column.

Create UC on columns (name, deleted) and (flavorid, deleted)

Replace Select then Insert -> Try to Insert.

blueprint db-enforce-unique-keys

Change-Id: If66d2f1387c2b2748784bf7ac9746b8d755b70a9
Merge "Remove race condition (in InstanceTypes)"