SONIC CLI for CLI-Sessions feature

[i-davydenko]

HLD: https://github.com/sonic-net/SONiC/pull/1367

Module name	PR	state	context
sonic-buildimage	Dev cli sessions
sonic-host-services	cli-sessions
sonic-utilities	SONIC CLI for CLI-Sessions feature #3175

What I did

Implement next commands for CLI-sessions feature:

• config serial-console inactivity-timeout

• config serial-console sysrq-capabilities

• show serial-console

• config ssh max-sessions

• config ssh inactivity-timeout

• show ssh

How I did it

Write handlers in config/main.py for serial-console and ssh commands to cover configuration set; Write handlers in show/main.py for serial-console and ssh to cover show commands.

How to verify it

Manual tests

Previous command output (if the output of a command-line utility has changed)

n/a

New command output (if the output of a command-line utility has changed)

n/a

[qiluo-msft]

Please resolve conflicts. #Closed

[i-davydenko]

/azpw run Azure.sonic-utilities

[mssonicbld]

/AzurePipelines run Azure.sonic-utilities

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[fastiuk]

@qiluo-msft , you approved all the rest. Could you please approve that one?