Optimize ORM updates and deletes for simple tables

[aaronc]

In #11525, update and delete for bank balances is significantly slower with the ORM than a manual implementation because the ORM naively assumes that we always need to get and unmarshal the existing object to update and delete indexes. This is a safe general assumption, but we should add an optimization for cases where this isn't needed like bank balance and supply.

One complexity is making sure gas consumption is deterministic (already tracked in #11088). The ORM should have a well specified gas consumption model regardless of any read optimizations an implementation is able make.