UART SLIP Wrapper API

btstack_uart_slip_wrapper.h : Compatibility layer to use new H5 implementation with btstack_uart.h implementations without SLIP support. Using this compatibility layer caused increased processing as it uses single byte UART reads.

If you're using H5, please consider implement the H5/SLIP functions in your btstack_uart.h or hal_uart_dma.h implementation.

/**
 * @brief Initialize SLIP wrapper for existing btstack_uart_block_t instance without SLIP support
 * @param uart_block_without_slip
 * @returns btstack_uart_t instance with SLIP support for use with hci_trasnport_h5
 */
const btstack_uart_t * btstack_uart_slip_wrapper_instance(const btstack_uart_t * uart_without_slip);