MLBEDSW-6961: Bypass functionality for memory ops

- In order to solve output diffs, the Reshape op was pushed
to the CPU. The problem was that the Mean op ifm shape
was replaced by the Reshape op ifm shape.

- This limitation is now removed. Changed implementation
how memory only ops are bypassed. Always replace the memory
only op ifm tensor with its ofm tensor. By doing this
the ifm tensor for the operator that is after the memory only
op is never changed.

Signed-off-by: Johan Alfven <johan.alfven@arm.com>
Change-Id: Ibcdebf33fd9b7a37f90984a129500b5dac52e5ea