Add packet validity checks

[bmcdonnell]

Add some basic NTP packet validity checks.

[khoih-prog]

Thanks for this PR. It seems to be a good improvements, but I have to spend some time to test and see if everything is working OK with the new PR.

Best Regards,

[khoih-prog]

The test for this PR is so far OK.

Testing with Nano_33_IoT

Before and after update with this PR => OK

NINA_NTPClient_Basic started @ IP address: 192.168.2.114
Using NTP Server pool.ntp.org
******NOT UPDATED******
UTC : 00:00:04
UTC : 00:00:04 Thu 01 Jan 1970
LOC : 02:28:20
LOC : 02:28:20 Sun 07 Feb 2106
UTC EPOCH : 4
LOC EPOCH : 4294952900
UTC : 0:0:4 Thu 1/1/1970 or 1 Jan 1970
UTC : 00:00:04 Thu 1/1/1970 or 1 Jan 1970
LOC : 2:28:20 Sun 7/2/2106 or 7 Feb 2106
LOC : 02:28:20 Sun 7/2/2106 or 7 Feb 2106
********UPDATED********
UTC : 05:20:35
UTC : 05:20:35 Fri 04 Jun 2021
LOC : 01:20:35
LOC : 01:20:35 Fri 04 Jun 2021
UTC EPOCH : 1622784035
LOC EPOCH : 1622769635
UTC : 5:20:35 Fri 4/6/2021 or 4 Jun 2021
UTC : 05:20:35 Fri 4/6/2021 or 4 Jun 2021
LOC : 1:20:35 Fri 4/6/2021 or 4 Jun 2021
LOC : 01:20:35 Fri 4/6/2021 or 4 Jun 2021
********UPDATED********
UTC : 05:20:45
UTC : 05:20:45 Fri 04 Jun 2021
LOC : 01:20:45
LOC : 01:20:45 Fri 04 Jun 2021
UTC EPOCH : 1622784045
LOC EPOCH : 1622769645
UTC : 5:20:45 Fri 4/6/2021 or 4 Jun 2021
UTC : 05:20:45 Fri 4/6/2021 or 4 Jun 2021
LOC : 1:20:45 Fri 4/6/2021 or 4 Jun 2021
LOC : 01:20:45 Fri 4/6/2021 or 4 Jun 2021

Testing with MBED NANO_RP2040_CONNECT

Before and after update with this PR => OK

Starting NINA_NTPClient_Basic on MBED NANO_RP2040_CONNECT with WiFiNINA using WiFiNINA_Generic Library
Connecting to: HueNet1

NINA_NTPClient_Basic started @ IP address: 192.168.2.153
Using NTP Server pool.ntp.org
******NOT UPDATED******
UTC : 00:00:04
UTC : 00:00:04 Thu 01 Jan 1970
LOC : 02:28:20
LOC : 02:28:20 Sun 07 Feb 2106
UTC EPOCH : 4
LOC EPOCH : 4294952900
UTC : 0:0:4 Thu 1/1/1970 or 1 Jan 1970
UTC : 00:00:04 Thu 1/1/1970 or 1 Jan 1970
LOC : 2:28:20 Sun 7/2/2106 or 7 Feb 2106
LOC : 02:28:20 Sun 7/2/2106 or 7 Feb 2106
********UPDATED********
UTC : 05:22:52
UTC : 05:22:52 Fri 04 Jun 2021
LOC : 01:22:52
LOC : 01:22:52 Fri 04 Jun 2021
UTC EPOCH : 1622784172
LOC EPOCH : 1622769772
UTC : 5:22:52 Fri 4/6/2021 or 4 Jun 2021
UTC : 05:22:52 Fri 4/6/2021 or 4 Jun 2021
LOC : 1:22:52 Fri 4/6/2021 or 4 Jun 2021
LOC : 01:22:52 Fri 4/6/2021 or 4 Jun 2021

I'm merging this PR and will create a new release to add support to RP2040-based boards.

Cheers,

[khoih-prog]

Approved. Tested OK.

[khoih-prog]

Just published the new NTPClient_Generic Releases v3.3.0).

Your Contribution has been noted in Contributions and Thanks

---

Releases v3.3.0

1. Add support to RP2040-based boards, such as RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040, using Earle Philhower's arduino-pico core.
2. Add support to RP2040-based boards, such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040, using Arduino-mbed RP2040 core.
3. Add packet validity checks
4. Add version string
5. Improve and add more debugging codes