Handle special symbols in URLs

Certain mirrors will result in a 404 if special symbols are not handled safely according to the https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html#object-key-guidelines documentation.

Would be good to find a way to encode all URLs similar to how https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent handles it.

For example:

Normal:
`https://cdn77.cachyos.org/x86_64_v4/cachyos-core-v4/gcc-15.2.1+r604+g0b99615a8aef-2-x86_64_v3.pkg.tar.zst`

Encoded:
`https://cdn77.cachyos.org/repo/x86_64_v4/cachyos-v4/gcc-15.2.1%2Br604%2Bg0b99615a8aef-2-x86_64_v3.pkg.tar.zst`

See:
- https://github.com/CachyOS/distribution/issues/362