feat: support display HTML format in API error responses

[ruibaby]

What type of PR is this?

/kind feature
/area ui
/milestone 2.20.x

What this PR does / why we need it:

Add supports for display HTML format in API error responses

See #7115

Examples：

Which issue(s) this PR fixes:

Fixes #7115

Special notes for your reviewer:

Nginx mock example:

server {
    listen 80;
    server_name localhost;

    error_page   500 502 503 504  /50x.html;

    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    location / {
      proxy_pass http://localhost:8090;
      proxy_set_header HOST $host;
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }

    location ^~ /apis/content.halo.run/v1alpha1/posts/ {
        return 403;
    }
}

Does this PR introduce a user-facing change?

支持显示来自反向代理或者 WAF 的请求错误信息

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 57.19%. Comparing base (eff73dc) to head (b72b8fd).
Report is 79 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #7127      +/-   ##
============================================
+ Coverage     56.99%   57.19%   +0.20%     
- Complexity     3999     4047      +48     
============================================
  Files           714      719       +5     
  Lines         24110    24352     +242     
  Branches       1585     1598      +13     
============================================
+ Hits          13742    13929     +187     
- Misses         9756     9805      +49     
- Partials        612      618       +6     

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[guqing]

/lgtm

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JohnNiang]

/lgtm

[f2c-ci-robot]

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This pull-request has been approved by: JohnNiang

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