Instead of reading it in wget_http3_send_request, we'd rather do it in
wget_http3_get_response. We do this to fit into wget2's flow, where
wget_http_get_response_cb is called to retrieve the response.
* wget_http3_get_response returns the data that the http3 client stream has read
* all fprintf converted into debug_printf and error_printf
* fixed issues mentioned in the thread
* defined local and remote info_addr in wget_quic_st as local
* removed _set_async function call as it was redundant
* if wget_ssl_quic_open fails, closed the socket
* implemented log_printf using wget_debug_vprintf
* called wget_printf_exit if gnutls_rnd fails
* checked the input value of handshake_read()
* guarded functions and headers in quic.c and net.c using WITH_NGTCP2
* used wget_debug_printf and wget_error_printf in quic.c
* removed handshake_completed_db and handshake_confirmed_cb
* removed connection_write and connection_read
* implementated very basic callback functions for http3
* implemented wget_http3_send_request to create a http3 requests
* reimplemented the internal working of wget_queue_peak_untransmitted
* example code for sending http3 request implemented
* Added a bool in wget_byte struct named transmitted
* Implemented function wget_queue_peak_untransmitted_data
* This function will return first untransmitted byte
* Implemented wget_http3_deinit
* created http3.c and http3.h and implemented wget_http3_connection_st
* implemented http3 initialisation function to intialise the http3_connection struct
* shifted stream functions to a seperate stream.c file
* quic_write_read.c file created to demonstrate the working of wget_quic_read
and wget_quic_write hand in hand while configuring it to the QUIC ECHO server
* quic_write.c file created to make provide a example of write.
* A sample string initially pushed into the stream and then the stream
structure further utilised for sending the data over socket.
* Simplified the implementation of wget_quic_connect() and wget_ssl_quic_connect()
* Segregated the function wget_quic_connect into wget_quic_connect and wget_quic_handshake
