Functions shell_help_subcmd_print and shell_help_cmd_print
are more generic. Now they can operate on command passed as an
argument not hard coded active_cmd.
Signed-off-by: Jakub Rzeszutko <jakub.rzeszutko@nordisemi.no>
1. Created new shell module: shell_help.
2. Simplified command handlers with new shell print macros.
3. Removed help functions from command handlers.
Signed-off-by: Jakub Rzeszutko <jakub.rzeszutko@nordicsemi.no>