Added Port-channel name validations.

[ramachandrareddygaddam]

- What I did
Added port-channel name validations to the configuration commands.

- How I did it
Added more Port-channel name validations to the existing pull request #436.

1. The port-channel name should start with prefix 'PortChannel' and suffix <0-9999>.
2. Added Port-channel name suffix validation; valid suffix is 0-9999.
3. Interface validation is done when Interface added as a member of port-channel.
4. Added validation check when try to assign ipaddress to invalid port-channel name.

- How to verify it

User prompted with error for invalid port-channel configuration commands.

root@sonic:~# config portchannel add PortChan1000
Usage: config portchannel add [OPTIONS] <portchannel_name>

Error: PortChan1000 is invalid!, name should have prefix 'PortChannel' and suffix '<0-9999>'

root@sonic:~# config portchannel del PortChan1000
Usage: config portchannel del [OPTIONS] <portchannel_name>

Error: PortChan1000 is invalid!, name should have prefix 'PortChannel' and suffix '<0-9999>'

root@sonic:~# config portchannel member add PortChan1000 Ethernet0
Usage: config portchannel member add [OPTIONS] <portchannel_name> <port_name>

Error: PortChan1000 is invalid!, name should have prefix 'PortChannel' and suffix '<0-9999>'
root@sonic:~#

root@sonic:~# config portchannel member add PortChannel1 Etherne45
Usage: config portchannel member add [OPTIONS] <portchannel_name> <port_name>

Error: Interface name is invalid. Please enter a valid interface name!!
root@sonic:~#

root@sonic:~# config interface ip add PortChan1000 10.10.5.3/24
Usage: config interface ip add [OPTIONS] <interface_name> <ip_addr>

Error: 'interface_name' is not valid. Valid names [Ethernet/PortChannel/Vlan/Loopback]
root@sonic:~#

[stcheng]

retest this please

[jleveque]

Retest this please

[ramachandrareddygaddam]

Can you pl. let me know, what tests to be performed. Appreciate your help.

[jleveque]

@ramachandrareddygaddam: That comment is not directed at you. It is a trigger phrase which causes a GitHub plugin to automatically re-run our check builds.