feat: add support for scientific get_counters

[auspham]

What I did

Fix #19192 happens when the counters value gets too big and turns into scientific number

How I did it

Since value getting from counters_db will be serialise to string. The scientific number will be serialised to something like 1e+1.

As a result, doing int("1e+1") directly will throw an error. Since natural of scientific number is float. A fix is to convert "1e+1" to 10.0 first and then do int(10.0)

How to verify it

1. Sending large volume of traffic using traffic generator.
2. run "portstat" or "show interface count" or "sonic-clear counter" without seeing #19192

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

$ sudo ip netns exec asic2 portstat | grep -E 'IFACE|Ethernet256|Ethernet264'

Traceback (most recent call last):
  File "/usr/local/bin/portstat", line 675, in <module>
    main()
  File "/usr/local/bin/portstat", line 635, in main
    cnstat_dict, ratestat_dict = portstat.get_cnstat_dict()
  File "/usr/local/bin/portstat", line 151, in get_cnstat_dict
    self.collect_stat()
  File "/usr/local/lib/python3.9/dist-packages/utilities_common/multi_asic.py", line 157, in wrapped_run_on_all_asics
    func(self,  *args, **kwargs)
  File "/usr/local/bin/portstat", line 161, in collect_stat
    cnstat_dict, ratestat_dict = self.get_cnstat()
  File "/usr/local/bin/portstat", line 215, in get_cnstat
    cnstat_dict[port] = get_counters(port)
  File "/usr/local/bin/portstat", line 182, in get_counters
    fields[pos] = str(int(fields[pos]) + int(fvs[counter_name]))
ValueError: invalid literal for int() with base 10: '1.8342735403386e+14'

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

TBD

[yejianquan]

Hi @qiluo-msft , could you help to review this PR?

[auspham]

Hi @qiluo-msft could you please help reviewing?

[qiluo-msft]

The bug should be appear even earlier. fvs[counter_name] should not be assigned string of a float number like "1e+1".

[auspham]

Closes as already opened in #3420