Add array bounds and loop checks in postgres input

[fearful-symmetry]

Proposed commit message

Small PR that adds some array bounds checks to the postgres parser.

This also removes the usage of our custom nto* functions, as the golang functions will not panic if we're given an invalid array length.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works. Where relevant, I have used the stresstest.sh script to run them under stress conditions and race detector to verify their stability.
• I have added an entry in ./changelog/fragments using the changelog tool.

[elasticmachine]

Pinging @elastic/sec-linux-platform (Team:Security-Linux Platform)

[github-actions]

🤖 GitHub comments

Just comment with:

• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)

[github-actions]

@Mergifyio backport 8.19 9.2 9.3

[mergify]

backport 8.19 9.2 9.3

✅ Backports have been created

Details

• #48546 [8.19](backport #48528) Add array bounds and loop checks in postgres input has been created for branch 8.19
• #48547 [9.2](backport #48528) Add array bounds and loop checks in postgres input has been created for branch 9.2
• #48548 [9.3](backport #48528) Add array bounds and loop checks in postgres input has been created for branch 9.3