[Bug]: rd4_nl not supporting house extensions

[Avie238]

I Have A Problem With:

A specific source

What's Your Problem

I can't add an extension to the address i input (1A, 1B etc.) to the source eg. 6221BD 45C, this address cannot be added. The parameter that defines it the api request is house_number_extension.

I can make a PR for this just wanted to make sure it's ok

Source (if relevant)

No response

Logs

Relevant Configuration

Checklist Source Error

• Use the example parameters for your source (often available in the documentation) (don't forget to restart Home Assistant after changing the configuration)
• Checked that the website of your service provider is still working
• Tested my attributes on the service provider website (if possible)
• I have tested with the latest version of the integration (master) (for HACS in the 3 dot menu of the integration click on "Redownload" and choose master as version)

Checklist Sensor Error

• Checked in the Home Assistant Calendar tab if the event names match the types names (if types argument is used)

Required

• I have searched past (closed AND opened) issues to see if this bug has already been reported, and it hasn't been.
• I understand that people give their precious time for free, and thus I've done my very best to make this problem as easy as possible to investigate.