added wildcard handling for handle_external_mqtt_message

[ThatsLucas]

Describe your changes

This PR fixes the issue reported in #1712 where the MQTT message handler was not working with topics containing wildcards.
I used the already existing function 'check_topic_matches'

Issue ticket number and link

Checklist before requesting a review

• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• I read the contribution documentation and made sure that my changes meet its requirements

[james-ctc]

From memory it is deliberate design decision to not support wildcards on the internal EVerest api topics.
Wildcards should be supported for non EVerest api topics.

[ThatsLucas]

Oh ok, i'll avoid using them then.
Do you want me to close this PR ?

[Pietfried]

Hi @ThatsLucas , thanks for the contribution. It is ok to add wildcard support for external mqtt.

The current approach modifies execute_handlers_from_vector which affects both var_handlers and external mqtt messages but we would like to keep var_handlers separate.

handle_error_message is already considering wildcard topics, so we can make use of the same approach.

My suggestion is to define execute_handlers_from_vector_with_wildcards as a member function and use it within handle_error_message and handle_external_mqtt_message like:

void MessageHandler::handle_external_mqtt_message(const std::string& topic, const json& data) {
    execute_handlers_from_vector_with_wildcards(external_var_handlers, topic,
                                            [&](const auto& handler) { (*handler->handler)(topic, data); });
}

void MessageHandler::handle_error_message(const std::string& topic, const json& data) {
    execute_handlers_from_vector_with_wildcards(error_handlers, topic,
                                            [&](const auto& handler) { (*handler->handler)(topic, data); });
}

[ThatsLucas]

Hey @Pietfried thanks for the suggestion !

I made the requested change, looks good for me.
Just to double check, i had to change from

    std::map<MqttTopic, std::shared_ptr<TypedHandler>> error_handlers;  
to
    std::map<MqttTopic, std::vector<std::shared_ptr<TypedHandler>>>
        error_handlers; 

Is this the intended behavior, or was it meant to replace the handler each time?