Tests for esp now send timing.

Environment:

• hardware: ESP32-C3-MINI-1 (for both rx and tx)
• esp-idf version: v5.1-cbce221

WiFi initial configs are kept the same.

Before testing, use cargo espflash flash --bin rx --release --monitor to flash a receiver and fill its mac address to s_example_peer_mac of C code and RX_ADDR of Rust code. Keep the receiver running when testing.

Broadcast:

C version (set BENCH_UNICAST to 0):

Rust version (cargo espflash flash --bin tx --release --monitor):

Unicast:

C Version (set BENCH_UNICAST to 1):

Rust version (cargo espflash flash --bin tx --features unicast --release --monitor):