[Bug]: xquic server doesn't reliably handle randomised CHLO (aka "Chaos Protection")

[koujaz]

What happened?

When a client tries to establish a connection with CHLO like this one (summary from wireshark):

Initial, DCID=a79a3ca80b9a8a81, PKN: 1, PADDING, PING, PING, PADDING, PING, CRYPTO, CRYPTO, PADDING, CRYPTO, CRYPTO, PADDING, CRYPTO, CRYPTO, PADDING

The xquic server fails to process the connection and in the log you will find:

[error] |scid:_|xqc_process_ping_frame|xqc_process_ping_frame error: ping frame shoud not be the first frame|
[error] |scid:_|xqc_process_frames|process frame error|-1|
[error] |scid:_|xqc_packet_decrypt_single|xqc_process_frames error|-1|
[error] |scid:_|xqc_conn_process_packet|process packets err|ret:-1|pos:00007FFF93B9F017|buf:00007FFF93B9F5C0|buf_size:1350| 
[error] |xqc_engine_packet_process|fail to process packets|conn:_|ret:-1|

Note the frames in CHLO are deliberately randomised and out-of-order (this is known as "chaos protection" https://quiche.googlesource.com/quiche/+/cb6b51054274cb2c939264faf34a1776e0a5bab7) but they make a valid QUIC packet.
Note xquic has built in some assumptions which seem unnecessary:

xquic/src/transport/xqc_frame.c

Line 861 in aef684c

"|xqc_process_ping_frame error: ping frame shoud not be the first frame|");

Steps To Reproduce

Take a client with "chaos protection" enabled (for example Google Quiche) and run connections against xquic server. In some cases the connection fails as described here.

Relevant log output