NacosPropertySourceConverter support

[hylexus]

enhancement

NacosPropertySourceConverter Support in issues#33

example

• yaml-based string in NacosServer

job:
  executor:
    app-name: demoJob
  scheduler:
    address: http://localhost:8899/schedule

• Load PropertySource from yaml-based string

// load property source
@NacosPropertySource(name = "jobConfig", dataId = "job.yml", autoRefreshed = true, first = true, converter = NacosPropertySourceConverter.SimpleYamlConverter.class)

• Reference in Java

@Value("${job.executor.app-name}")
private String name;

@NacosValue(value = "${job.scheduler.address}", autoRefreshed = true)
private String address;