cluster: fix TLS configs for tiproxy

[xhebox]

What problem does this PR solve?

1. server-tls of tidb is manually specified, so does tiproxy's server-tls. Instead, for newer tiproxy, server-http-tls should be specified.
2. topo.GlobalOptions.TLSEnabled is not passed to setTLSConfig.
3. remove schema:// and be consistent with tidb

Check List

Tests

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

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Release notes:

NONE

[codecov-commenter]

Codecov Report

Attention: 14 lines in your changes are missing coverage. Please review.

Comparison is base (30d4413) 55.43% compared to head (d64dbf0) 55.42%.

:exclamation: Current head d64dbf0 differs from pull request most recent head 653fb94. Consider uploading reports for the commit 653fb94 to get more accurate results

Files	Patch %	Lines
pkg/cluster/spec/tiproxy.go	0.00%	14 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2356 +/- ## ========================================== - Coverage 55.43% 55.42% -0.01% ========================================== Files 329 329 Lines 34838 34845 +7 ========================================== Hits 19310 19310 - Misses 13216 13223 +7 Partials 2312 2312 ``` | [Flag](https://app.codecov.io/gh/pingcap/tiup/pull/2356/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap) | Coverage Δ | | |---|---|---| | [tiup](https://app.codecov.io/gh/pingcap/tiup/pull/2356/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap) | `33.60% <ø> (ø)` | | | [unittest](https://app.codecov.io/gh/pingcap/tiup/pull/2356/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap) | `22.33% <0.00%> (-0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap#carryforward-flags-in-the-pull-request-comment) to find out more.

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[kaaaaaaang]

/lgtm

[kaaaaaaang]

/approve

[ti-chi-bot[bot]]

@xhebox: Your PR was out of date, I have automatically updated it for you.

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[kaaaaaaang]

/lgtm

[kaaaaaaang]

/approve

[ti-chi-bot[bot]]

[LGTM Timeline notifier]

Timeline:

• 2024-01-09 12:57:42.700564297 +0000 UTC m=+361652.284817983: :ballot_box_with_check: agreed by kaaaaaaang.
• 2024-01-10 08:11:57.320143046 +0000 UTC m=+430906.904396718: :heavy_multiplication_x::repeat: reset by xhebox.
• 2024-01-11 07:42:02.292582952 +0000 UTC m=+515511.876836638: :ballot_box_with_check: agreed by kaaaaaaang.

[ti-chi-bot[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kaaaaaaang

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