server: support PROXY protocol fallback-able options

[blacktear23]

What problem does this PR solve?

Issue Number: close #41409

Problem Summary:

Add -proxy-protocol-fallbackable option to let TiDB can handle raw connection connect to TiDB and the IP address is in allowed IP list.

What is changed and how it works?

update go-proxyprotocol package to enable fallbackable support.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

Add `-proxy-protocol-fallbackable` options to let TiDB can handle raw connection which client IP is in PROXY protocol allowed IP list.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• djshow832
• xhebox

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[ti-chi-bot]

Hi @blacktear23. Thanks for your PR.

I'm waiting for a pingcap member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[xhebox]

/run-check-issue-triage-complete

[xhebox]

/test all

[xhebox]

/test all

[xhebox]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 3af1bb6

[xhebox]

/cherry-pick release-6.5
/cherry-pick release-6.6

[ti-chi-bot]

@xhebox: new pull request created to branch release-6.5: #41570.

In response to this:

/cherry-pick release-6.5
/cherry-pick release-6.6

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

@xhebox: new pull request created to branch release-6.6: #41571.

In response to this:

/cherry-pick release-6.5
/cherry-pick release-6.6

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.