Rename timing connect phase label to Connect

[ryanfowler]

Summary

• Render the timing connect phase as Connect instead of TCP in the waterfall and verbose debug output.
• Update the README wording and timing-related tests to match the new label.
• Adjust the timing unit test alignment expectation because the longer label shifts the bar start.

Testing

• cargo fmt
• cargo clippy --locked --all-targets --all-features -- -D warnings
• cargo test --all-features timing
• cargo test --all-features --test integration socks_proxy_unix_socket_timing_and_grpc_binary_cases -- --test-threads=1