[Spytest] Adapt to 'show interfaces status' change

[lolyu]

Description of PR

A new column FEC is introduced to show interfaces status output,
adjust the template to adapt to the change.

Signed-off-by: Longxiang Lyu lolv@microsoft.com

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Approach

What is the motivation for this PR?

To adapt to the new column FEC in the output from show int status:

  Interface            Lanes    Speed    MTU    FEC         Alias    Vlan    Oper    Admin             Type    Asym PFC
-----------  ---------------  -------  -----  -----  ------------  ------  ------  -------  ---------------  ----------
  Ethernet0      33,34,35,36     100G   9100     rs   Ethernet1/1  routed      up       up  QSFP28 or later         off
  Ethernet4      37,38,39,40     100G   9100     rs   Ethernet2/1  routed    down     down  QSFP28 or later         off
  Ethernet8      41,42,43,44     100G   9100     rs   Ethernet3/1  routed    down     down  QSFP28 or later         off
 Ethernet12      45,46,47,48     100G   9100     rs   Ethernet4/1  routed    down     down  QSFP28 or later         off
 Ethernet16      49,50,51,52     100G   9100     rs   Ethernet5/1  routed    down     down  QSFP28 or later         off
 Ethernet20      53,54,55,56     100G   9100     rs   Ethernet6/1  routed    down     down  QSFP28 or later         off
...

How did you do it?

How did you verify/test it?

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation