[caffe2] allow passing options to the DB in Save operations (#55935)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55935
Add a new `DB::SetOptions()` method to allow passing options to the DB as part
of Save operations. This can be used for passing in options to control the
serialization behavior, such as rate limits or other parameters. The
serialization options are passed is an opaque string, so that different DB
implementations may choose their own options and options format.
This also adds a new `db_options` parameter to the `Save` operator.
This allows users to pass in the DB options when saving data.
ghstack-source-id: 126589771
Test Plan:
I don't have any tests in this diff since no DB implements options yet. The
next diff in the stack includes an options implementation, along with unit
tests that verify the options are passed in correctly.
Differential Revision: D27729461
fbshipit-source-id: 4d03250c389c66a049cdee1d05e082f5649ac0f0
