T6375: Fix/Update NAT logging (backport #3493)

[mergify]

Change Summary

Fixed broken logging for "show log nat"

Added the following commands:
show log nat source
show log nat source rule <ruleNum>
show log nat destination nat
show log nat destination nat rule <ruleNum>
show log nat static
show log nat static rule <ruleNum>

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

https://vyos.dev/T6257

Related PR(s)

Component(s) name

nat, log

Proposed changes

This change will fix the broken show log nat, as well as add additional show log nat commands with filtering on source/destination/static

How to test

Configure NAT and run show commands:

vyos@vyos:~$ show log nat
May 21 05:45:40 kernel: [SRC-NAT-15-MASQ]IN= OUT=eth0.101 SRC=10.5.5.5 DST=4.2.2.2 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=38271 DF PROTO=ICMP TYPE=8 CODE=0 ID=30181 SEQ=1
May 21 05:51:39 kernel: [STATIC-SRC-NAT-10]IN= OUT=eth0.101 SRC=10.5.5.5 DST=4.2.2.2 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=11281 DF PROTO=ICMP TYPE=8 CODE=0 ID=32481 SEQ=1
May 21 05:53:17 kernel: [STATIC-DST-NAT-10]IN=eth0.101 OUT= MAC=0c:11:a6:1d:00:00:64:9d:99:d2:08:53:08:00 SRC=192.168.2.21 DST=10.0.101.235 LEN=60 TOS=0x00 PREC=0x00 TTL=127 ID=16028 PROTO=ICMP TYPE=8 CODE=0 ID=208 SEQ=34739
May 21 13:49:51 kernel: [DST-NAT-10]IN=eth0.101 OUT= MAC=0c:11:a6:1d:00:00:64:9d:99:d2:08:53:08:00 SRC=192.168.2.21 DST=10.0.101.235 LEN=52 TOS=0x00 PREC=0x00 TTL=127 ID=19424 DF PROTO=TCP SPT=15495 DPT=22 WINDOW=64240 RES=0x00 SYN URGP=0

vyos@vyos:~$ show log nat source
May 21 05:45:40 kernel: [SRC-NAT-15-MASQ]IN= OUT=eth0.101 SRC=10.5.5.5 DST=4.2.2.2 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=38271 DF PROTO=ICMP TYPE=8 CODE=0 ID=30181 SEQ=1

vyos@vyos:~$ show log nat source rule 15
May 21 05:45:40 kernel: [SRC-NAT-15-MASQ]IN= OUT=eth0.101 SRC=10.5.5.5 DST=4.2.2.2 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=38271 DF PROTO=ICMP TYPE=8 CODE=0 ID=30181 SEQ=1

Smoketest result

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

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This is an automatic backport of pull request #3493 done by [Mergify](https://mergify.com).