[mlir] separable registration of attribute and type interfaces

It may be desirable to provide an interface implementation for an attribute or
a type without modifying the definition of said attribute or type. Notably,
this allows to implement interfaces for attributes and types outside of the
dialect that defines them and, in particular, provide interfaces for built-in
types. Provide the mechanism to do so.

Currently, separable registration requires the attribute or type to have been
registered with the context, i.e. for the dialect containing the attribute or
type to be loaded. This can be relaxed in the future using a mechanism similar
to delayed dialect interface registration.

See https://llvm.discourse.group/t/rfc-separable-attribute-type-interfaces/3637

Depends On D104233

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D104234