EPD-190: Cleanup: warnings and unused imports
EPD-190: Update PastTrackSettings to implement its corresponding observer interface
EPD-190: Update GUICommonSettings to implement its corresponding observer interface.
EPD-190: Cleanup
EPD-190: Update AisHandlerCommonSettings to implement its corresponding observer interface.
EPD-190: Update HandlerSettings to implement its corresponding listener interface
EPD-190: minor
EPD-190: Update IntendedRouteHandlerCommonSettings to implement its corresponding listener interface.
EPD-190: Update MetocHandlerCommonSettings to implement its corresponding listener interface.
EPD-190: Update MSIHandlerCommonSettings to implement its corresponding listener interface.
EPD-190: Update RouteManagerCommonSettings to implement its corresponding listener interface.
EPD-190: Update NetworkSettings to implement its corresponding listener interface
EPD-190: Update ExternalSensorsCommonSettings to implement its corresponding listener interface + fixed its code style/layout.