Is your feature request related to a problem? Please describe.

Does need to upgrade junit 4 to junit 5?

See #4193 if we upgrade the project's test to junit 5, some test feature like @Nested annotation can be used.

Describe the solution you'd like

• change the maven dependencies
• change the import in java code
• change the ci

Additional context

awaitility use junit 4, see
https://github.com/apolloconfig/apollo/blob/master/pom.xml#L282-L285

<dependency>
			<groupId>org.awaitility</groupId>
			<artifactId>awaitility</artifactId>
			<scope>test</scope>
		</dependency>

We need to investigate that awaitility can use junit 5 or not.