XX-11202: Expose CDR, MyBuddy, Proxy, Registrar, SAA, REST server REST API services management

refactor code, externalize prompts management and settings management. Services that needs to manage prompts and settings should only extend PromptsApi / ServiceSettingsApi
Implementations should extend BaseServiceApiImpl

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

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

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

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

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

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