Make schema part of RegisterOperators::Options (#26114)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26114
With this diff, the operator schema or name can be specified as part of the options objects:
```
static auto registry = torch::RegisterOperators()
.op(torch::RegisterOperators::options().schema("my_op").kernel(&kernel))
.op(...);
```
This does not break backwards compatibility, all old APIs are kept as shorthands.
This (a) makes the API more consistent, accumulating all options into the options objects and not treating schema special anymore, and (b) this is required for allowing the c10 dispatcher to forward registration calls to ATenDispatch for ops that are still on that dispatcher, see plan in https://github.com/pytorch/pytorch/issues/24132
ghstack-source-id: 90049402
Test Plan: unit tests
Differential Revision: D17350383
fbshipit-source-id: cbb8f33a52dccb2a4522753e7b5ac8ba35b908fd
