Add simple tests to benchmark

[Kludex]

I'd like to try this for a bit, if I observe myself not caring, then I'll drop it.

[codspeed-hq[bot]]

CodSpeed Performance Report

Congrats! CodSpeed is installed 🎉

🆕 18 new benchmarks were detected.

You will start to see performance impacts in the reports once the benchmarks are run from your default branch.

Detected benchmarks

• test_100_continue_sent_when_body_consumed[h11]: 1.6 ms
• test_100_continue_sent_when_body_consumed[httptools]: 1.3 ms
• test_chunked_encoding[h11]: 1.6 ms
• test_chunked_encoding[httptools]: 1.5 ms
• test_early_response[h11]: 1.6 ms
• test_early_response[httptools]: 1.5 ms
• test_get_request[h11]: 1.5 ms
• test_get_request[httptools]: 1.5 ms
• test_http10_request[h11]: 1.6 ms
• test_http10_request[httptools]: 1.5 ms
• test_keepalive[h11]: 1.5 ms
• test_keepalive[httptools]: 1.5 ms
• test_large_post_request[h11]: 2.1 ms
• test_large_post_request[httptools]: 1.7 ms
• test_pipelined_requests[h11]: 2.1 ms
• test_pipelined_requests[httptools]: 1.7 ms
• test_post_request[h11]: 1.6 ms
• test_post_request[httptools]: 1.5 ms