Fixes interpolation on SafeBuffer

Interpolation was untested and did not work with hash arguments.

Adds
- support for interpolation with hash argument
- tests for the above
- tests for safe/unsafe interpolation
Merge pull request #13321 from mezis/fix-safebuffer-interpolation-master

Fixes interpolation on SafeBuffer
Create a blacklist to disallow mutator methods to be delegated to `Array`.

This change was necessary because the whitelist wouldn't work.
It would be painful for users trying to update their applications.

This blacklist intent to prevent odd bugs and confusion in code that call mutator
methods directely on the `Relation`.