alsaucm: Add list1 command for non-tuple lists

alsaucm: Add list1 command for non-tuple lists

snd_use_case_get_list returns lists of strings that are either:
a) A sequence of single strings
b) A sequence of pairs of strings all flattened into a single list

The current list command assumes layout (b) above, and hence prints
nothing when printing a single-entry list that's actually in layout (a).
Add a new command "list1" to dump lists in layout (a).

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>