tls13: Upstream various fix in prototype

- Adjust max input_max_frag_len
- Guard transform_negotiate
- Adjust function position
- update comments
- fix wrong requirements

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 0109f77..3295e67 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -2805,11 +2805,10 @@
 
     switch( ssl->state )
     {
-        /*
-         * ssl->state is initialized as HELLO_REQUEST. It is the same
-         * as CLIENT_HELLO state.
-         */
         case MBEDTLS_SSL_HELLO_REQUEST:
+            mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_HELLO );
+            break;
+
         case MBEDTLS_SSL_CLIENT_HELLO:
             ret = mbedtls_ssl_write_client_hello( ssl );
             break;