[mlir] Support repeated delayed registration of dialect interfaces

Dialects themselves do not support repeated addition of interfaces with the
same TypeID. However, in case of delayed registration, the registry may contain
such an interface, or have the same interface registered several times due to,
e.g., dependencies. Make sure we delayed registration does not attempt to add
an interface with the same TypeID more than once.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D96606