Scope BatchSpecExecutionCacheEntries to users
Created by: mrnugget
This is stacked on top of #28671 and scopes cache entries to users.
This adds a foreign key, user_id
, to the cache entries table to scope all cache entries per user.
The other solution I had in mind was to simply prefix every cache-key with the user-id. Wouldn't require any database changes. But I'm on the fence as to what the best solution is.