Fix stack-show failed with a name in uuid format

We should get the information by stack_name after got 'None' queried by
stack_id, because heat support the stack_name in uuid format.

Change-Id: I1cf8abe2f8091e056cc621ad5c3f80a8a1da656a
Closes-Bug: #1296606
Merge "Fix stack-show failed with a name in uuid format"