Extracting reflection operations to a façade class

Closes #845. The motivation for this pull request are described in related issue.

The code inside serialization package needs to be refactored because we have a lot of injection points for `ReflectionProvider`. But I think this change can be done in another pull request after this.

We can schedule this change to 4.2 release because we change internal API.
here and probably other... (it'll not be proxied)