Support max-qname-len option

[Mygod]

Fixes #1. Supersedes #3.

[FDeghy]

Queries reach the server, but the server does not respond to the queries and Server-failure is received on the client side after timeout at dns server.

[patterniha]

#1 (comment)

so we don't need this option at all :)

[Mygod]

Good. Regarding #5 (comment), it appears that picoquic requires a minimum packet length for initial packet so that's why it didn't work: (PICOQUIC_ENFORCED_INITIAL_MTU = 129)

    /* Create a connection context if the CI is acceptable */
    if (packet_length < PICOQUIC_ENFORCED_INITIAL_MTU) {
        /* Unexpected packet. Reject, drop and log. */
        ret = PICOQUIC_ERROR_INITIAL_TOO_SHORT;
    }

[Mygod]

Unfortunately, the 101-byte limit leaves only a 56-byte MTU, rendering running QUIC (especially for the handshake) quite difficult. This will be a difficult change to implement on this codebase.