Bluetooth: AT: Rename API's which uses term 'stream'

Rename the API's with 'list' which uses the term 'stream'.
For example 'at_open_stream' is renamed to 'at_open_list' and
the same applies for other API's which uses 'stream' in it.

Change-Id: I62bed70de3d85cd4890b10e04eba27ae2de1907c
Signed-off-by: Sathish Narasimman <sathish.narasimman@intel.com>