UART fixes

[SpComb]

Various small fixes for uart tx:

• Fix stdio to use uart_write() and not block unnecessarily on uart_write_all()
• Remove uart_write_all() and uart_write_buffered()
• Avoid potential issues with pre-existing task notify state on uart_tx_flush()
• Fix use of critical section for TX buffer vs FIFO checks in uart_tx_fast()
• Fix use of critical section in uart_tx_one()
  • This was bypassing the TX buffer, which could have lead to corrupted output
  • This was using a potentially blocking xStreamBufferSend() call inside a critical section
• Pass explicit timeout parameter to all uart read/write/flush/close calls
• Fix console timeout on esp32
• Fix console stop -> stdout/stderr flush/sync