@Override
	public void setApplicationContext(ApplicationContext applicationContext) {
		this.applicationContext = applicationContext;
	}
On application start up, NacosContextRefresher add nacos listeners to all application
level dataIds, when there is a change in the data, listeners will refresh
configurations.

@author juven.xuxb
@author pbting
@author freeman
spring-cloud-alibaba-starters/spring-alibaba-nacos-config/src/main/java/com/alibaba/cloud/nacos/refresh/NacosContextRefresher.java