modbus_controller button component to send fixed command without expected answer

**Describe the problem you have/What new integration you would like**

I need a modbus_controller button component to be able to send a single command to a device.

**Please describe your use case for this integration and alternatives you've tried:**

As a user, I would like to be able to save the parameter of my Aldes Inspirair ventilation system.
As described in the Modbus documentation for this device, I have to write value $1234 to register $14.
To do so, a push button in the user interface might be useful.

**Additional context**

I can't find an easy way to do so currently but button component seems to be a good candidate.
However there is no button in modbus_controller yet.

Start by reviewing the modbus_controller documentation and how existing components send Modbus commands. Define the button behavior for writing value $1234 to register $14, including the case where no response is expected, and verify that the requested fixed-command use case is covered.

Written by the indexing model from the issue text.