[Doc] add milliseconds_diff func and update file external table according to v3.1.9 and 3.2.4 rn (backport #42437) (backport #42439) (backport #42447) (backport #42462)

[mergify]

This is an automatic backport of pull request #42462 done by Mergify.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

[mergify]

Cherry-pick of 39618e1 has failed:

On branch mergify/bp/branch-2.5/pr-42462
Your branch is up to date with 'origin/branch-2.5'.

You are currently cherry-picking commit 39618e1043.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   docs/en/data_source/file_external_table.md
	modified:   docs/en/reference/System_variable.md
	modified:   docs/en/sql-reference/sql-functions/function-list.md
	new file:   docs/en/sql-reference/sql-functions/like-predicate-functions/regexp_extract_all.md
	modified:   docs/zh/reference/System_variable.md
	modified:   docs/zh/sql-reference/sql-functions/function-list.md
	new file:   docs/zh/sql-reference/sql-functions/like-predicate-functions/regexp_extract_all.md

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   docs/docusaurus/sidebars.json

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[CLAassistant]

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1 out of 2 committers have signed the CLA.

✅ evelynzhaojie
❌ mergify[bot]
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[mergify]

@mergify[bot]: Backport conflict, please reslove the conflict and resubmit the pr