Use ScopedStream to return the same stream during the lifetime of the
RAII object. This allows us to create events outside a user submitted
func, and submit work within the user submitted func, since the stream
given to the user from urQueueGetNativeHandle is guaranteed to be the
same stream that we record events on.

All entry points unsupported for now.

Add Entry Point to UR interface loaders

Allow some params to be nullptr.

Also update docs to add an entry in ur_structure_type_t.

And update Native CPU DDI table

In order to manage native memory migration across ur_mem_handle_ts, we
need to know which ur_mem_handle_ts are wrapped up in the void *
function data.

As is done in oneapi-src#1711, we don't need to wait on events that are not given
directly to UR by the user through the phEventWaitList param.

Add urEnqueueNativeCommand impl for HIP adapter. Also cahnge typo
'quard' to 'guard'.

In line with changing from a sync op to async for memory migration
across devices in a context.

Check that deps work before and after standard UR enqueue calls.