Add leaf snowflake key generator and related functions.

Author: wgy8283335

sharding-orchestration/sharding-orchestration-core/src/test/java/org/apache/shardingsphere/integration/test/LeafSegmentKeyGeneratorTest.java sharding-orchestration/sharding-orchestration-core/src/test/java/org/apache/shardingsphere/integration/test/LeafSegmentKeyGeneratorIT.java

@@ -36,7 +36,7 @@
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
 
-public final class LeafSegmentKeyGeneratorTest {
+public final class LeafSegmentKeyGeneratorIT {
 
     private LeafSegmentKeyGenerator leafSegmentKeyGenerator = new LeafSegmentKeyGenerator();
 

sharding-orchestration/sharding-orchestration-core/src/test/java/org/apache/shardingsphere/integration/test/LeafSnowflakeKeyGeneratorTest.java sharding-orchestration/sharding-orchestration-core/src/test/java/org/apache/shardingsphere/integration/test/LeafSnowflakeKeyGeneratorIT.java

@@ -45,7 +45,7 @@
 import static org.junit.Assert.assertThat;
 
 @FixMethodOrder(value = MethodSorters.NAME_ASCENDING)
-public final class LeafSnowflakeKeyGeneratorTest {
+public final class LeafSnowflakeKeyGeneratorIT {
 
     private LeafSnowflakeKeyGenerator leafSnowflakeKeyGenerator = new LeafSnowflakeKeyGenerator();