backend, net: replace tidb/parser/mysql

[djshow832]

What problem does this PR solve?

Issue Number: close #358

Problem Summary:
Using tidb/parser/mysql, go-mysql-org/go-mysql/mysql, and pnet at the same time may cause problems, such as errors.Is(err, mysql.ErrMalformPacket) may unexpectedly return false.

What is changed and how it works:

• Add server_status.go
• Replace most of the usage of tidb/parser/mysql with go-mysql-org/go-mysql/mysql and pnet

Check List

Tests

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

Code refactor, no tests.

Notable changes

• Has configuration change
• Has HTTP API interfaces change
• Has tiproxyctl change
• Other user behavior changes

Release note

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

None

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: xhebox

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [xhebox]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-12-15 12:36:08.446088662 +0000 UTC m=+618859.483315589: ☑️ agreed by xhebox.