[FIX] Multibyte query support

[adamist521]

Describe the bug

I get following error when I input multibyte character when querying.

error in process sentinel: Multibyte text in HTTP request: POST /api/chat?client=emacs HTTP/1.1
MIME-Version: 1.0
Connection: keep-alive
Host: 127.0.0.1:42110
Accept-encoding: gzip
Accept: */*
User-Agent: URL/Emacs Emacs/29.1 (Mac; aarch64-apple-darwin23.4.0)
Authorization: Bearer YOUR_KHOJ_CLOUD_API_KEY
Content-Type: application/json
Content-length: 23

{"q":"日本語いけますか?","n":8}

To Reproduce

• Input Multibyte Char(in my case Japanese) to Chat (Query) to Khoj

Platform

• Server:
  • Cloud-Hosted (https://app.khoj.dev)
  • Self-Hosted Docker
  • Self-Hosted Python package
  • Self-Hosted source code
• Client:
  • Obsidian
  • Emacs
  • Desktop app
  • Web browser
  • WhatsApp
• OS:
  • Windows
  • macOS
  • Linux
  • Android
  • iOS

If self-hosted

• Server Version [e.g. 1.0.1]: v1.24.1

Additional context

Searching around, I've found some issues seems to relate to this bug so I'll list it below.

• Multi-byte char handling with url-retrieve is broken karthink/gptel#4
• chinese support rksm/org-ai#3
• Request failure when prompt has special characters, like accented characters or cedilla karthink/gptel#2