To inject the `Resolver` similar to the `TransformContext`. I need the
`Resolver` in the new `aws_s3` source. I figured I'd submit this change
separately since it was easy to pull out and I wanted thoughts sooner
than later.

Alternatively, it seems like the resolver is static now so we could drop
it from `SinkContext` and `TransformContext`. I wanted some confirmation
on that front though. I'm happy to reverse this and remove injection of
the `Resolver`.

Signed-off-by: Jesse Szwedko <jesse@szwedko.me>

Signed-off-by: Jesse Szwedko <jesse@szwedko.me>