Add retry logic when rate limited by server

[shrobon]

[shrobon]

Here's an example with imgur

• Program does not retry
• Still progresses with the download and generates a file with 0 bytes.
• Progress tracker shows NaN%

╰─ go run . -url https://i.imgur.com/jSFlqda.jpeg
Response status: 429 Too Many Requests
Server does not support range requests. Using 1 thread for download
File size: 0 MB, Parallelism: 1
Total time taken 68.027ms
Progress: NaN% (0/0 MB) ✅