Extends the bt_conn_le_create_param struct to provide the option
to set a custom timeout for the initiation of the connection.
The logic for the default values of window_coded and interval_coded
were moved to conn.c in order to resolve all defaults for the
create_param struct at a single location.
Timeout is not added as a parameter to the BT_CONN_LE_CREATE_PARAM
macro due to the expectation that CONFIG_BT_CREATE_CONN_TIMEOUT
will be the typical value that users will expect.
Fixes#23468
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>