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
• 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%.

❗ 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 ⚠️

Additional details and impacted files

@@            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	Coverage Δ
tiup	33.60% <ø> (ø)
unittest	22.33% <0.00%> (-0.01%)	⬇️

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[kaaaaaaang]

/lgtm

[kaaaaaaang]

/approve

[ti-chi-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@xhebox: Your PR was out of date, I have automatically updated it for you.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]

[LGTM Timeline notifier]

Timeline:

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

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kaaaaaaang

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