[BUG]: Messy code when Inspect unicode character by `DevToolsPlugin`

[SongOfYouth]

Description

Expected behaviour

get messy code.

Actual behaviour

show the unicode character correctly.

Steps to reproduce

Inspect any request which contains unicode character(ex."你好") response.

Dev Proxy Version

2.1.0

Operating system (environment)

Windows

Shell

PowerShell

Configuration file

    {
      "name": "DevToolsPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "devTools"
    },

"devTools": {
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.1.0/devtoolsplugin.schema.json",
  "preferredBrowser": "Chrome"
}

Additional Info

No response

[waldekmastykarz]

Thanks for raising this @SongOfYouth. Let us try to see if we can repro it using your suggestion and take it from there.

[waldekmastykarz]

Thanks for reporting this. I can reproduce the issue. It happens when the API response doesn't include charset=utf-8 in the Content-Type header (eg. application/json vs. application/json; charset=utf-8). The underlying proxy library defaults to ISO-8859-1 (per the obsolete RFC 2616), while RFC 8259 requires JSON to be UTF-8 encoded. We should default to UTF-8 when no charset is specified.