[202012] [portstat, intfstat] added rates and utilization

[vadymhlushko-mlnx]

What I did

Backport the pull/1750 to 202012 branch

Depends on sonic-swss-common/pull/330

According to HLD added calculation of rates and utilization columns to the portstat and intfstat scripts output

How I did it

Modified the portstat and intfstat scripts

How to verify it

Added UT

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

admin@sonic:~$ show int count
      IFACE    STATE    RX_OK    RX_BPS    RX_UTIL    RX_ERR    RX_DRP    RX_OVR    TX_OK    TX_BPS    TX_UTIL    TX_ERR    TX_DRP    TX_OVR
-----------  -------  -------  --------  ---------  --------  --------  --------  -------  --------  ---------  --------  --------  --------
  Ethernet0        X        0       N/A        N/A         0         0       N/A        0       N/A        N/A         0         0       N/A
  Ethernet2        U      287       N/A        N/A         0         0       N/A      818       N/A        N/A         0         0       N/A
  Ethernet4        U      380       N/A        N/A         0         0       N/A      858       N/A        N/A         0         0       N/A
  Ethernet6        U      286       N/A        N/A         0         0       N/A      850       N/A        N/A         0         0       N/A

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

admin@sonic:~$ show int count
      IFACE    STATE    RX_OK      RX_BPS    RX_UTIL    RX_ERR    RX_DRP    RX_OVR    TX_OK      TX_BPS    TX_UTIL    TX_ERR    TX_DRP    TX_OVR
-----------  -------  -------  ----------  ---------  --------  --------  --------  -------  ----------  ---------  --------  --------  --------
  Ethernet0        X        0    0.00 B/s      0.00%         0         0       N/A        0    0.00 B/s      0.00%         0         0       N/A
  Ethernet2        U        0    0.00 B/s      0.00%         0         0       N/A        0    0.00 B/s      0.00%         0         0       N/A
  Ethernet4        U        0    0.00 B/s      0.00%         0         0       N/A        0    0.00 B/s      0.00%         0         0       N/A
  Ethernet6        U        0    0.00 B/s      0.00%         0         0       N/A        0    0.00 B/s      0.00%         0         0       N/A

[lgtm-com]

This pull request introduces 1 alert when merging c67b00b into a9c6970 - view on LGTM.com

new alerts:

• 1 for Unused import

[liat-grozovik]

@qiluo-msft could you please help to approve and merge?