Add command line parameter for QUIC flood control

[avevad]

No description provided.

[github-actions]

Potential issues:

1. Possible null actor use when applying --quic-flood-control:
   • validator-engine/validator-engine.hpp:423 calls td::actor::send_closure(quic_.get(), ...) without checking that quic_ is initialized.
   • validator-engine/validator-engine.cpp:5638 enqueues this call in acts, which are executed immediately after ValidatorEngine creation (before run() and before start_rldp() creates quic_).
   • Risk: quic_ is null when the closure is sent, which likely crashes or silently drops the option.
   • Suggestion: store the options in ValidatorEngine (e.g., pending_quic_options_) and apply them inside start_rldp() after quic_ is created, or guard set_quic_options to cache if quic_ is empty.

If you want, I can propose a concrete patch for the deferred apply.

[github-actions]

--quic-flood-control is applied before quic_ exists. acts are executed immediately after ValidatorEngine actor creation, but quic_ is only created in start_rldp(). So set_quic_options() forwards to an empty actor and the option is either dropped or triggers a bad send. This makes the new CLI flag ineffective at startup. Consider storing the options in ValidatorEngine and applying them in start_rldp() (or pass options into the QuicSender ctor), and guard when quic_ isn’t initialized.
Files: validator-engine/validator-engine.hpp:423, validator-engine/validator-engine.cpp:5638

[Kotoff82]

952ff6e