include/uipc: Implement uipc module as extension of ipc module

include/uipc: Implement uipc module as extension of ipc module

The uipc module contains several functions that are identical with
their ipc-counterpart. This kind of code-duplication can be avoided
using the new interface/implements mechanism.

This commit modifies the uipc module so that it extends the interface
provided by the ipc module, reusing methods of the ipc module where
possible.