XX-11204: Expose DNS and MWI management REST API

DNS REST API
- api/dns/settings GET to retrieve all settings
- api/dns/settings/{settingPath} GET, DELETE, PUT to retrieve, reset or change setting value
- api/dns/advisor/server/{serverId} GET to retrieve DNS advisor result

MWI REST API
- api/mwi/settings GET to retrieve all MWI settings
- api/mwi/settings/{settingPath} GET, DELETE, PUT to retrieve, reset or change setting value