Add new print stat function

[timeforplanb123]

Add new print_stat function:

• function prints statistic for Result object
• recursive function, that will correctly process any AggregatedResult, MultiResult, Result objects and skip non-AggregatedResult, non-MultiResult, non-Result objects
• has result and count parameters:
  • result is Result object
  • count is the same that count from print_result. It's number of sorted results (-5 or 5, for example). It can be useful for a large number of identical results. It's acceptable to use numbers with minus sign(-5 as example), then results will be from the end of results list.

print_stat looks like (with color scheme):

netmiko_send_command************************************************************
* dev_1 ************************************************************************
    netmiko_send_command                ok=1               changed=0               failed=0              
* dev_2 ************************************************************************
    netmiko_send_command                ok=1               changed=0               failed=0              

OK      : 2
CHANGED : 0
FAILED  : 0

[dbarrosop]

Same as with other PRs, commits are mixed somehow

[timeforplanb123]

Replaced all new functions to single PR with ipynb examples #21