Root client FB as a device

[viacheslauK]

Summary

Converts the MQTT broker connection point from a top-level function block (MQTTClientFB) into an openDAQ device (OpenDAQMQTTDevice) added via instance.addDevice("daq.mqtt://<host>[:<port>]"). The publisher, subscriber and JSON decoder FBs are unchanged.

Changes

• MqttStreamingModule implements onGetAvailableDeviceTypes / onCreateDevice in place of the function-block pair.
• Port precedence: a port in the connection string wins over the Port property and is written back into it.
• MqttClientFbImpl : FunctionBlock → MqttClientDeviceImpl : Device (files renamed), with a DeviceType, a separate CreateDefaultConfig(), and onGetInfo. Nested FB offering is unchanged.
• Connection state moved to the device connection status container (addConfigurationConnectionStatus, surfaced as ConfigurationStatus).
• Properties: BrokerAddress removed (host comes from the connection string), BrokerPort renamed to Port and documented as the fallback when the connection string has no port.
• test_mqtt_client_fb.cpp → test_mqtt_client_device.cpp, rewritten around addDevice and extended with connection-string, DeviceInfo and ConfigurationStatus cases.

Notes

• Breaking change: addFunctionBlock("MQTTClientFB", ...) no longer works and BrokerAddress is gone; callers must use addDevice("daq.mqtt://...").

[denise-opendaq]

looks good to me. just one note
I created the device. and subscriber fb
then when im trying to remove the subscriber fb I have an exception

Exception in Tkinter callback
Traceback (most recent call last):
  File "/opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/tkinter/__init__.py", line 2074, in __call__
    return self.func(*args)
           ~~~~~~~~~^^^^^^^
  File "/Users/deniserokhin/projects/openDAQ/examples/applications/python/GUI Application/gui_demo.py", line 704, in <lambda>
    command=lambda: self.handle_tree_menu_remove_function_block(node)
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/Users/deniserokhin/projects/openDAQ/examples/applications/python/GUI Application/gui_demo.py", line 1018, in handle_tree_menu_remove_function_block
    parent_fb.remove_function_block(node)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
RuntimeError: Device does not allow adding/removing function blocks. [ /root/opendaq/build/_deps/opendaq-src/core/opendaq/device/include/opendaq/device_impl.h:886 ]
 - Caused by: [ /root/opendaq/build/_deps/opendaq-src/core/opendaq/signal/include/opendaq/signal_container_impl.h:640 ]
 - Caused by: [ /Users/deniserokhin/projects/openDAQ/core/opendaq/signal/include/opendaq/signal_container_impl.h:640 ]

with publisher the same issue

to fix it you have override void onRemoveFunctionBlock(const FunctionBlockPtr& functionBlock) method

another question can Publisher create JSONConfig, so it will be easier to check subcriber?

but its working :)