[mlir][linalg] Create a dedicated target for `LinalgRelayoutInterface` (#128485)
Creates an interface target for `LinalgRelayoutInterface`. This is
primarily to reduce the dependency of `Tensor` on `Linalg` to the
required minimum. For context and rationale, see:
* https://github.com/llvm/llvm-project/issues/127668
Note, I also took the liberty of renaming `LinalgRelayoutInterface` as
`RelayoutOpInterface` (removed `Linalg`, added `Op`).