[Feature] Add test case for PageRank/DegreeCentrality/WCC/Kcore algorithms

[coderzc]

Feature Description (功能描述)

Add test case for PageRank/DegreeCentrality/WccTest/Lpa/Kcore algorithms, please refer:

incubator-hugegraph-computer/computer-test/src/main/java/org/apache/hugegraph/computer/algorithm/community/trianglecount/TriangleCountTest.java

Line 36 in c806528

public class TriangleCountTest extends AlgorithmTestBase {

[conghuhu]

I want to try, plz assign to me, thanks.

[coderzc]

LPA test has been implemented by #237