R1:32942f623250

Introduce storage patch "phases" to allow index-rebuilding patches to execute after worker queue schema changes

Summary:
Ref T13591. Some storage patches queue worker tasks, currently always to rebuild search indexes.

These patches can not execute in creation order if a later patch modifies the worker task table, since they'll try to perform a modern INSERT against an out-of-date table schema. Such a modification is desirable in the context of T13591, but making it causes these patches to fail.

Patches…