Move IPC memory API from dpctl.ipc to dpctl.memory

Migrate the SYCL IPC memory functionality from the standalone
dpctl.ipc.IPCMemoryHandle class into methods on dpctl.memory._Memory:

- _Memory.get_ipc_handle()
- _Memory.open_ipc_handle(...)
- _Memory.close_ipc_mapping()

Signed-off-by: Zhan Xue <zhan.xue@intel.com>

Author: zxue2

dpctl/CMakeLists.txt

@@ -206,4 +206,3 @@ target_link_libraries(DpctlCAPI INTERFACE ${_trgt}_headers)
 add_subdirectory(program)
 add_subdirectory(memory)
 add_subdirectory(utils)
-add_subdirectory(ipc)

dpctl/_backend.pxd

@@ -596,6 +596,7 @@ cdef extern from "syclinterface/dpctl_sycl_extension_interface.h":
         DPCTLSyclWorkGroupMemoryRef Ref)
 
     cdef bint DPCTLWorkGroupMemory_Available()
+    cdef bint DPCTLIPCMem_Available()
 
     cdef struct DPCTLOpaqueRawKernelArg
     ctypedef DPCTLOpaqueRawKernelArg *DPCTLSyclRawKernelArgRef