dnsmasq: migrate to MVC/API

[fichtner]

Important notices

Before you add a new report, we ask you kindly to acknowledge the following:

• I have read the contributing guide lines at https://github.com/opnsense/core/blob/master/CONTRIBUTING.md
• I am convinced that my issue is new after having checked both open and closed issues at https://github.com/opnsense/core/issues?q=is%3Aissue

Is your feature request related to a problem? Please describe.

We cannot extend Dnsmasq without creating further maintenance concerns.

Describe the solution you like

Do the migration now. Add features later.

Describe alternatives you considered

Add features now. Do the migration later. Just kidding. ;)

Additional context

Add any other context or screenshots about the feature request here or links to relevant forum thread or similar