[decode-syseeprom] When reading from DB, display CRC-32 and all Vendor Extensions

[jleveque]

What I did

Changes when reading system EEPROM values from State DB (decode-syseeprom -d):

• Display CRC-32
• Display all present vendor extensions
• Display hex TLV code with lower-case x to match the output when reading directly from EEPROM
• If a TLV code is not available, omit it from the output rather than displaying 'N/A' for all fields

How to verify it

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

admin@sonic:~$ sudo decode-syseeprom -d
TlvInfo Header:
   Id String:    TlvInfo
   Version:      1
   Total Length: 170
TLV Name             Code      Len  Value
-------------------  ------  -----  --------------------------
Product Name         0X21        8  S6100-ON
Part Number          0X22        6  0F6N2R
Serial Number        0X23       20  TH0F6N2RCET0007600NG
Base MAC Address     0X24        6  0C:29:EF:CF:AC:A0
Manufacture Date     0X25       19  07/07/2020 15:05:34
Device Version       0X26        1  1
Label Revision       0X27        3  A08
Platform Name        0X28       26  x86_64-dell_s6100_c2538-r0
ONIE Version         0X29        8  3.15.1.0
MAC Addresses        0X2A        2  384
Manufacturer         0X2B        5  CET00
Manufacture Country  0X2C        2  TH
Vendor Name          0X2D        4  DELL
Diag Version         0X2E        8  3.25.4.1
Service Tag          0X2F        7  F3CD9Z2

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

admin@sonic:~$ sudo decode-syseeprom -d
TlvInfo Header:
   Id String:    TlvInfo
   Version:      1
   Total Length: 170
TLV Name             Code      Len  Value
-------------------  ------  -----  --------------------------
Product Name         0x21        8  S6100-ON
Part Number          0x22        6  0F6N2R
Serial Number        0x23       20  TH0F6N2RCET0007600NG
Base MAC Address     0x24        6  0C:29:EF:CF:AC:A0
Manufacture Date     0x25       19  07/07/2020 15:05:34
Device Version       0x26        1  1
Label Revision       0x27        3  A08
Platform Name        0x28       26  x86_64-dell_s6100_c2538-r0
ONIE Version         0x29        8  3.15.1.0
MAC Addresses        0x2A        2  384
Manufacturer         0x2B        5  CET00
Manufacture Country  0x2C        2  TH
Vendor Name          0x2D        4  DELL
Diag Version         0x2E        8  3.25.4.1
Service Tag          0x2F        7  F3CD9Z2
Vendor Extension     0xFD        7
CRC-32               0xFE        4  0xAC518FB3