Fix display disorder problem of show mirror_session

[pettershao-ragilenetworks]

What I did

Fix display disorder problem of show mirror_session

The problem is as follows, the span session and erspan session are not sorted in the name column(Take SPAN as an example, ERSPAN is similar)：

root@sonic:/home/admin# show mirror_session

ERSPAN Sessions
Name    Status    SRC IP    DST IP    GRE    DSCP    TTL    Queue    Policer    Monitor Port    SRC Port    Direction
------  --------  --------  --------  -----  ------  -----  -------  ---------  --------------  ----------  -----------

SPAN Sessions
Name       Status    DST Port    SRC Port    Direction    Queue    Policer
---------  --------  ----------  ----------  -----------  -------  ---------
session1   active    Ethernet30  Ethernet40  both
session11  active    Ethernet9   Ethernet10  rx
session15  active    Ethernet2   Ethernet3   tx
session2   active    Ethernet7   Ethernet8   both
root@sonic:/home/admin# 

How I did it

Sort the name column with natsorted

How to verify it

use “show mirror_session”

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

root@sonic:/home/admin# show mirror_session 
ERSPAN Sessions
Name    Status    SRC IP    DST IP    GRE    DSCP    TTL    Queue    Policer    Monitor Port    SRC Port    Direction
------  --------  --------  --------  -----  ------  -----  -------  ---------  --------------  ----------  -----------

SPAN Sessions
Name       Status    DST Port    SRC Port    Direction    Queue    Policer
---------  --------  ----------  ----------  -----------  -------  ---------
session1   active    Ethernet30  Ethernet40  both
session11  active    Ethernet9   Ethernet10  rx
session15  active    Ethernet2   Ethernet3   tx
session2   active    Ethernet7   Ethernet8   both
root@sonic:/home/admin# 

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

root@sonic:/home/admin# show mirror_session 
ERSPAN Sessions
Name    Status    SRC IP    DST IP    GRE    DSCP    TTL    Queue    Policer    Monitor Port    SRC Port    Direction
------  --------  --------  --------  -----  ------  -----  -------  ---------  --------------  ----------  -----------

SPAN Sessions
Name       Status    DST Port    SRC Port    Direction    Queue    Policer
---------  --------  ----------  ----------  -----------  -------  ---------
session1   active    Ethernet30  Ethernet40  both
session2   active    Ethernet7   Ethernet8   both
session11  active    Ethernet9   Ethernet10  rx
session15  active    Ethernet2   Ethernet3   tx

[lgtm-com]

This pull request introduces 7 alerts when merging 0c98b3b into 25fda26 - view on LGTM.com

new alerts:

• 4 for Unused import
• 2 for 'import *' may pollute namespace
• 1 for Unused local variable

[pettershao-ragilenetworks]

@prsunny @dgsudharsan please review, Thanks!

[pettershao-ragilenetworks]

could you please review this change? Thanks!@prsunny @dgsudharsan

[prsunny]

@bingwang-ms for viz