SNC-3888: mask the password/key in cli command history

[kwangsuk]

Enhance Klish parser to mask the password/key values in the command history.
As of now, masking is applied to the commands which have the keyword - password/key/auth-password/priv-password. It can be extended as needed.

• username password role }
• radius-server key
• tacacs-server key
• snmp-server user [encrypted] auth [md5|sha] auth-password priv [aes-128 | des] priv-password

configure terminal
username dellemc password ***** role admin
radius-server key *****
tacacs-server key *****
snmp-server user dellemc auth md5 auth-password *****