chore: update proxy URLs to use TON Studio CDN

[rahulyadav-57]

Resolves #250

[xpyctumo]

Results:

✅ Templates
❌ Import from GitHub (Network error)

Access to XMLHttpRequest at 'https://codeload.github.com/tact-lang/jetton/zip/refs/heads/main' (redirected from 'https://cdn-ide-github.tonstudio.io/tact-lang/jetton/archive/refs/heads/main.zip') from origin 

'%host%' has been blocked by CORS policy: The 'Access-Control-Allow-Origin' header has a value 'https://render.githubusercontent.com' that is not equal to the supplied origin.
            
            
GET https://codeload.github.com/tact-lang/jetton/zip/refs/heads/main net::ERR_FAILED

[verytactical]

Conflicts